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  • Normal map lighting bug in bottom right quadrant

    - by Ryan Capote
    I am currently working on getting normal maps working in my project, and have run into a problem with lighting. As you can see, the normals in the bottom right quadrant of the lighting isn't calculating the correct direction to the light or something. Best seen by the red light If I use flat normals (z normal = 1.0), it seems to be working fine: normals for the tile sheet: Shader: #version 330 uniform sampler2D uDiffuseTexture; uniform sampler2D uNormalsTexture; uniform sampler2D uSpecularTexture; uniform sampler2D uEmissiveTexture; uniform sampler2D uWorldNormals; uniform sampler2D uShadowMap; uniform vec4 uLightColor; uniform float uConstAtten; uniform float uLinearAtten; uniform float uQuadradicAtten; uniform float uColorIntensity; in vec2 TexCoords; in vec2 GeomSize; out vec4 FragColor; float sample(vec2 coord, float r) { return step(r, texture2D(uShadowMap, coord).r); } float occluded() { float PI = 3.14; vec2 normalized = TexCoords.st * 2.0 - 1.0; float theta = atan(normalized.y, normalized.x); float r = length(normalized); float coord = (theta + PI) / (2.0 * PI); vec2 tc = vec2(coord, 0.0); float center = sample(tc, r); float sum = 0.0; float blur = (1.0 / GeomSize.x) * smoothstep(0.0, 1.0, r); sum += sample(vec2(tc.x - 4.0*blur, tc.y), r) * 0.05; sum += sample(vec2(tc.x - 3.0*blur, tc.y), r) * 0.09; sum += sample(vec2(tc.x - 2.0*blur, tc.y), r) * 0.12; sum += sample(vec2(tc.x - 1.0*blur, tc.y), r) * 0.15; sum += center * 0.16; sum += sample(vec2(tc.x + 1.0*blur, tc.y), r) * 0.15; sum += sample(vec2(tc.x + 2.0*blur, tc.y), r) * 0.12; sum += sample(vec2(tc.x + 3.0*blur, tc.y), r) * 0.09; sum += sample(vec2(tc.x + 4.0*blur, tc.y), r) * 0.05; return sum * smoothstep(1.0, 0.0, r); } float calcAttenuation(float distance) { float linearAtten = uLinearAtten * distance; float quadAtten = uQuadradicAtten * distance * distance; float attenuation = 1.0 / (uConstAtten + linearAtten + quadAtten); return attenuation; } vec3 calcFragPosition(void) { return vec3(TexCoords*GeomSize, 0.0); } vec3 calcLightPosition(void) { return vec3(GeomSize/2.0, 0.0); } float calcDistance(vec3 fragPos, vec3 lightPos) { return length(fragPos - lightPos); } vec3 calcLightDirection(vec3 fragPos, vec3 lightPos) { return normalize(lightPos - fragPos); } vec4 calcFinalLight(vec2 worldUV, vec3 lightDir, float attenuation) { float diffuseFactor = dot(normalize(texture2D(uNormalsTexture, worldUV).rgb), lightDir); vec4 diffuse = vec4(0.0); vec4 lightColor = uLightColor * uColorIntensity; if(diffuseFactor > 0.0) { diffuse = vec4(texture2D(uDiffuseTexture, worldUV.xy).rgb, 1.0); diffuse *= diffuseFactor; lightColor *= diffuseFactor; } else { discard; } vec4 final = (diffuse + lightColor); if(texture2D(uWorldNormals, worldUV).g > 0.0) { return final * attenuation; } else { return final * occluded(); } } void main(void) { vec3 fragPosition = calcFragPosition(); vec3 lightPosition = calcLightPosition(); float distance = calcDistance(fragPosition, lightPosition); float attenuation = calcAttenuation(distance); vec2 worldPos = gl_FragCoord.xy / vec2(1024, 768); vec3 lightDir = calcLightDirection(fragPosition, lightPosition); lightDir = (lightDir*0.5)+0.5; float atten = calcAttenuation(distance); vec4 emissive = texture2D(uEmissiveTexture, worldPos); FragColor = calcFinalLight(worldPos, lightDir, atten) + emissive; }

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  • Arcball Problems with UDK

    - by opdude
    I'm trying to re-create an arcball example from a Nehe, where an object can be rotated in a more realistic way while floating in the air (in my game the object is attached to the player at a distance like for example the Physics Gun) however I'm having trouble getting this to work with UDK. I have created an LGArcBall which follows the example from Nehe and I've compared outputs from this with the example code. I think where my problem lies is what I do to the Quaternion that is returned from the LGArcBall. Currently I am taking the returned Quaternion converting it to a rotation matrix. Getting the product of the last rotation (set when the object is first clicked) and then returning that into a Rotator and setting that to the objects rotation. If you could point me in the right direction that would be great, my code can be found below. class LGArcBall extends Object; var Quat StartRotation; var Vector StartVector; var float AdjustWidth, AdjustHeight, Epsilon; function SetBounds(float NewWidth, float NewHeight) { AdjustWidth = 1.0f / ((NewWidth - 1.0f) * 0.5f); AdjustHeight = 1.0f / ((NewHeight - 1.0f) * 0.5f); } function StartDrag(Vector2D startPoint, Quat rotation) { StartVector = MapToSphere(startPoint); } function Quat Update(Vector2D currentPoint) { local Vector currentVector, perp; local Quat newRot; //Map the new point to the sphere currentVector = MapToSphere(currentPoint); //Compute the vector perpendicular to the start and current perp = startVector cross currentVector; //Make sure our length is larger than Epsilon if (VSize(perp) > Epsilon) { //Return the perpendicular vector as the transform newRot.X = perp.X; newRot.Y = perp.Y; newRot.Z = perp.Z; //In the quaternion values, w is cosine (theta / 2), where //theta is the rotation angle newRot.W = startVector dot currentVector; } else { //The two vectors coincide, so return an identity transform newRot.X = 0.0f; newRot.Y = 0.0f; newRot.Z = 0.0f; newRot.W = 0.0f; } return newRot; } function Vector MapToSphere(Vector2D point) { local float x, y, length, norm; local Vector result; //Transform the mouse coords to [-1..1] //and inverse the Y coord x = (point.X * AdjustWidth) - 1.0f; y = 1.0f - (point.Y * AdjustHeight); length = (x * x) + (y * y); //If the point is mapped outside of the sphere //( length > radius squared) if (length > 1.0f) { norm = 1.0f / Sqrt(length); //Return the "normalized" vector, a point on the sphere result.X = x * norm; result.Y = y * norm; result.Z = 0.0f; } else //It's inside of the sphere { //Return a vector to the point mapped inside the sphere //sqrt(radius squared - length) result.X = x; result.Y = y; result.Z = Sqrt(1.0f - length); } return result; } DefaultProperties { Epsilon = 0.000001f } I'm then attempting to rotate that object when the mouse is dragged, with the following update code in my PlayerController. //Get Mouse Position MousePosition.X = LGMouseInterfacePlayerInput(PlayerInput).MousePosition.X; MousePosition.Y = LGMouseInterfacePlayerInput(PlayerInput).MousePosition.Y; newQuat = ArcBall.Update(MousePosition); rotMatrix = MakeRotationMatrix(QuatToRotator(newQuat)); rotMatrix = rotMatrix * LastRot; LGMoveableActor(movingPawn.CurrentUseableObject).SetPhysics(EPhysics.PHYS_Rotating); LGMoveableActor(movingPawn.CurrentUseableObject).SetRotation(MatrixGetRotator(rotMatrix));

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  • Assign sage variable values into R objects via sagetex and Sweave

    - by sheed03
    I am writing a short Sweave document that outputs into a Beamer presentation, in which I am using the sagetex package to solve an equation for two parameters in the beta binomial distribution, and I need to assign the parameter values into the R session so I can do additional processing on those values. The following code excerpt shows how I am interacting with sage: <<echo=false,results=hide>>= mean.raw <- c(5, 3.5, 2) theta <- 0.5 var.raw <- mean.raw + ((mean.raw^2)/theta) @ \begin{frame}[fragile] \frametitle{Test of Sage 2} \begin{sagesilent} var('a1, b1, a2, b2, a3, b3') eqn1 = [1000*a1/(a1+b1)==\Sexpr{mean.raw[1]}, ((1000*a1*b1)*(1000+a1+b1))/((a1+b1)^2*(a1+b1+1))==\Sexpr{var.raw[1]}] eqn2 = [1000*a2/(a2+b2)==\Sexpr{mean.raw[2]}, ((1000*a2*b2)*(1000+a2+b2))/((a2+b2)^2*(a2+b2+1))==\Sexpr{var.raw[2]}] eqn3 = [1000*a3/(a3+b3)==\Sexpr{mean.raw[3]}, ((1000*a3*b3)*(1000+a3+b3))/((a3+b3)^2*(a3+b3+1))==\Sexpr{var.raw[3]}] s1 = solve(eqn1, a1,b1) s2 = solve(eqn2, a2,b2) s3 = solve(eqn3, a3,b3) \end{sagesilent} Solutions of Beta Binomial Parameters: \begin{itemize} \item $\sage{s1[0]}$ \item $\sage{s2[0]}$ \item $\sage{s3[0]}$ \end{itemize} \end{frame} Everything compiles just fine, and in that slide I am able to see the solutions to the three equations respective parameters in that itemized list (for example the first item in the itemized list from that beamer slide is outputted as [a1=(328/667), b1=(65272/667)] (I am not able to post an image of the beamer slide but I hope you get the idea). I would like to save the parameter values a1,b1,a2,b2,a3,b3 into R objects so that I can use them in simulations. I cannot find any documentation in the sagetex package on how to save output from sage commands into variables for use with other programs (in this case R). Any suggestions on how to get these values into R?

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  • Problem with Matlab functions

    - by appi
    HI. I got this matlab functionWhen I ran it, the following error messege showed up. Can anybody give me some hint? Thank you. The code is also shown below. [h,im_matched,theta,I,J]=im_reg_MI('keyframe1.jpg','keyframe2.jpg', 0, 1) ??? Undefined function or variable "h". Error in == im_reg_MI at 74 [a, b] = max(h(:));% finding the max of MI and indecises Below is the code. [h,im_matched, theta,I,J]=im_reg_MI(image1, image2, angle, step) [m,n]=size(image1); [p,q]=size(image2); [a,b]=size(angle); im1=round(image1); for k=1:b J = rotate_image(angle(k),image2); %rotated cropped IMAGE2 image21=round(J); [m1,n1]=size(image21); for i=1:step:(m1-m) for j=1:step:(n1-n) im2=image21(i:(i+m-1),j:(j+n-1)); % selecting part of IMAGE2 matching the size of IMAHE1 im2=round(im2); h(k,i,j)=MI2(im1,im2); % calculating MI end end end [a, b] = max(h(:));% finding the max of MI and indecises

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  • How to transform gameObjects in array?

    - by user1764781
    I have an array of available gameObjects in the scene. An array of GO should be transformed according to received floats through UDP connection. I know it is simple, but can't figure it out how to accomplish the transformation an array of GO according to received unique floats for each GO, any help will be appreciated. Here is a transformation floats, it might be helpful I guess: x =ReadSingleBigEndian(data, signalOffset); signalOffset+=4; y= ReadSingleBigEndian(data, signalOffset); signalOffset+=4; z= ReadSingleBigEndian(data, signalOffset); signalOffset+=4; alpha= ReadSingleBigEndian(data, signalOffset); signalOffset+=4; theta= ReadSingleBigEndian(data,signalOffset); signalOffset+=4; phi= ReadSingleBigEndian(data,signalOffset); signalOffset+=4;

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  • Surface normal to screen angle

    - by Tannz0rz
    I've been struggling to get this working. I simply wish to take a surface normal and convert it to a screen angle. As an example, assuming we're working with the highlighted surface on the sphere below, where the arrow is the normal, the 2D angle would obviously be PI/4 radians. Here's one of the many things I've tried to no avail: float4 A = v.vertex; float4 B = v.vertex + float4(v.normal, 0.0); A = mul(VP, A); B = mul(VP, B); A.xy = (0.5 * (A.xy / A.w)) + 0.5; B.xy = (0.5 * (B.xy / B.w)) + 0.5; o.theta = atan2(B.y - A.y, B.x - A.x); I'm finally at my wit's end. Thanks for any and all help.

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  • Big Oh notation does not mention constant value

    - by user883561
    I am a programmer and have just started reading Algorithms. I am not completely convinced with the notations namely Bog Oh, Big Omega and Big Theta. The reason is by definition of Big Oh, it states that there should be a function g(x) such that it is always greater than or equal to f(x). Or f(x) <= c.n for all values of n n0. My doubt is the why dont we mention the constant value in the definition? For example. lets say a function 6n+4, we denote it as O(n). but its not true that the definition holds good for all constant value. this holds good only when c = 10 and n = 1. For lesser values of c than 6, the value of n0 increases. So why we do not mention the constant value as a part of the definition.

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  • about Master theorem

    - by matin1234
    Hi this is the link http://www.cs.mcgill.ca/~cs251/OldCourses/1997/topic5/ is written that for T(n)<=2n+T(n/3)+T(n/3) the T(n) is not O(n) but with master theorem we can use case 3 and we can say that its T(n) is theta(n) please help me! thanks how can we prove that T(n) is not O(n)

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  • Perturb vector by some angle

    - by Myx
    Hello: I have a unit vector in 3D space whose direction I wish to perturb by some angle within the range 0 to theta, with the position of the vector remaining the same. What is a way I can accomplish this? Thanks.

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  • How to prove worst-case number of inversions in a heap is O(nlogn)?

    - by Jacques
    I am busy preparing for exams, just doing some old exam papers. The question below is the only one I can't seem to do (I don't really know where to start). Any help would be appreciated greatly. Use the O(nlogn) comparison sort bound, the theta(n) bound for bottom-up heap construction, and the order complexity if insertion sort to show that the worst-case number of inversions in a heap is O(nlogn).

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  • Valgrind says "stack allocation," I say "heap allocation"

    - by Joel J. Adamson
    Dear Friends, I am trying to trace a segfault with valgrind. I get the following message from valgrind: ==3683== Conditional jump or move depends on uninitialised value(s) ==3683== at 0x4C277C5: sparse_mat_mat_kron (sparse.c:165) ==3683== by 0x4C2706E: rec_mating (rec.c:176) ==3683== by 0x401C1C: age_dep_iterate (age_dep.c:287) ==3683== by 0x4014CB: main (age_dep.c:92) ==3683== Uninitialised value was created by a stack allocation ==3683== at 0x401848: age_dep_init_params (age_dep.c:131) ==3683== ==3683== Conditional jump or move depends on uninitialised value(s) ==3683== at 0x4C277C7: sparse_mat_mat_kron (sparse.c:165) ==3683== by 0x4C2706E: rec_mating (rec.c:176) ==3683== by 0x401C1C: age_dep_iterate (age_dep.c:287) ==3683== by 0x4014CB: main (age_dep.c:92) ==3683== Uninitialised value was created by a stack allocation ==3683== at 0x401848: age_dep_init_params (age_dep.c:131) However, here's the offending line: /* allocate mating table */ age_dep_data->mtable = malloc (age_dep_data->geno * sizeof (double *)); if (age_dep_data->mtable == NULL) error (ENOMEM, ENOMEM, nullmsg, __LINE__); for (int j = 0; j < age_dep_data->geno; j++) { 131=> age_dep_data->mtable[j] = calloc (age_dep_data->geno, sizeof (double)); if (age_dep_data->mtable[j] == NULL) error (ENOMEM, ENOMEM, nullmsg, __LINE__); } What gives? I thought any call to malloc or calloc allocated heap space; there is no other variable allocated here, right? Is it possible there's another allocation going on (the offending stack allocation) that I'm not seeing? You asked to see the code, here goes: /* Copyright 2010 Joel J. Adamson <[email protected]> $Id: age_dep.c 1010 2010-04-21 19:19:16Z joel $ age_dep.c:main file Joel J. Adamson -- http://www.unc.edu/~adamsonj Servedio Lab University of North Carolina at Chapel Hill CB #3280, Coker Hall Chapel Hill, NC 27599-3280 This file is part of an investigation of age-dependent sexual selection. This code is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with haploid. If not, see <http://www.gnu.org/licenses/>. */ #include "age_dep.h" /* global variables */ extern struct argp age_dep_argp; /* global error message variables */ char * nullmsg = "Null pointer: %i"; /* error message for conversions: */ char * errmsg = "Representation error: %s"; /* precision for formatted output: */ const char prec[] = "%-#9.8f "; const size_t age_max = AGEMAX; /* maximum age of males */ static int keep_going_p = 1; int main (int argc, char ** argv) { /* often used counters: */ int i, j; /* read the command line */ struct age_dep_args age_dep_args = { NULL, NULL, NULL }; argp_parse (&age_dep_argp, argc, argv, 0, 0, &age_dep_args); /* set the parameters here: */ /* initialize an age_dep_params structure, set the members */ age_dep_params_t * params = malloc (sizeof (age_dep_params_t)); if (params == NULL) error (ENOMEM, ENOMEM, nullmsg, __LINE__); age_dep_init_params (params, &age_dep_args); /* initialize frequencies: this initializes a list of pointers to initial frqeuencies, terminated by a NULL pointer*/ params->freqs = age_dep_init (&age_dep_args); params->by = 0.0; /* what range of parameters do we want, and with what stepsize? */ /* we should go from 0 to half-of-theta with a step size of about 0.01 */ double from = 0.0; double to = params->theta / 2.0; double stepsz = 0.01; /* did you think I would spell the whole word? */ unsigned int numparts = floor(to / stepsz); do { #pragma omp parallel for private(i) firstprivate(params) \ shared(stepsz, numparts) for (i = 0; i < numparts; i++) { params->by = i * stepsz; int tries = 0; while (keep_going_p) { /* each time through, modify mfreqs and mating table, then go again */ keep_going_p = age_dep_iterate (params, ++tries); if (keep_going_p == ERANGE) error (ERANGE, ERANGE, "Failure to converge\n"); } fprintf (stdout, "%i iterations\n", tries); } /* for i < numparts */ params->freqs = params->freqs->next; } while (params->freqs->next != NULL); return 0; } inline double age_dep_pmate (double age_dep_t, unsigned int genot, double bp, double ba) { /* the probability of mating between these phenotypes */ /* the female preference depends on whether the female has the preference allele, the strength of preference (parameter bp) and the male phenotype (age_dep_t); if the female lacks the preference allele, then this will return 0, which is not quite accurate; it should return 1 */ return bits_isset (genot, CLOCI)? 1.0 - exp (-bp * age_dep_t) + ba: 1.0; } inline double age_dep_trait (int age, unsigned int genot, double by) { /* return the male trait, a function of the trait locus, age, the age-dependent scaling parameter (bx) and the males condition genotype */ double C; double T; /* get the male's condition genotype */ C = (double) bits_popcount (bits_extract (0, CLOCI, genot)); /* get his trait genotype */ T = bits_isset (genot, CLOCI + 1)? 1.0: 0.0; /* return the trait value */ return T * by * exp (age * C); } int age_dep_iterate (age_dep_params_t * data, unsigned int tries) { /* main driver routine */ /* number of bytes for female frequencies */ size_t geno = data->age_dep_data->geno; size_t genosize = geno * sizeof (double); /* female frequencies are equal to male frequencies at birth (before selection) */ double ffreqs[geno]; if (ffreqs == NULL) error (ENOMEM, ENOMEM, nullmsg, __LINE__); /* do not set! Use memcpy (we need to alter male frequencies (selection) without altering female frequencies) */ memmove (ffreqs, data->freqs->freqs[0], genosize); /* for (int i = 0; i < geno; i++) */ /* ffreqs[i] = data->freqs->freqs[0][i]; */ #ifdef PRMTABLE age_dep_pr_mfreqs (data); #endif /* PRMTABLE */ /* natural selection: */ age_dep_ns (data); /* normalized mating table with new frequencies */ age_dep_norm_mtable (ffreqs, data); #ifdef PRMTABLE age_dep_pr_mtable (data); #endif /* PRMTABLE */ double * newfreqs; /* mutate here */ /* i.e. get the new frequency of 0-year-olds using recombination; */ newfreqs = rec_mating (data->age_dep_data); /* return block */ { if (sim_stop_ck (data->freqs->freqs[0], newfreqs, GENO, TOL) == 0) { /* if we have converged, stop the iterations and handle the data */ age_dep_sim_out (data, stdout); return 0; } else if (tries > MAXTRIES) return ERANGE; else { /* advance generations */ for (int j = age_max - 1; j < 0; j--) memmove (data->freqs->freqs[j], data->freqs->freqs[j-1], genosize); /* advance the first age-class */ memmove (data->freqs->freqs[0], newfreqs, genosize); return 1; } } } void age_dep_ns (age_dep_params_t * data) { /* calculate the new frequency of genotypes given additive fitness and selection coefficient s */ size_t geno = data->age_dep_data->geno; double w[geno]; double wbar, dtheta, ttheta, dcond, tcond; double t, cond; /* fitness parameters */ double mu, nu; mu = data->wparams[0]; nu = data->wparams[1]; /* calculate fitness */ for (int j = 0; j < age_max; j++) { int i; for (i = 0; i < geno; i++) { /* calculate male trait: */ t = age_dep_trait(j, i, data->by); /* calculate condition: */ cond = (double) bits_popcount (bits_extract(0, CLOCI, i)); /* trait-based fitness term */ dtheta = data->theta - t; ttheta = (dtheta * dtheta) / (2.0 * nu * nu); /* condition-based fitness term */ dcond = CLOCI - cond; tcond = (dcond * dcond) / (2.0 * mu * mu); /* calculate male fitness */ w[i] = 1 + exp(-tcond) - exp(-ttheta); } /* calculate mean fitness */ /* as long as we calculate wbar before altering any values of freqs[], we're safe */ wbar = gen_mean (data->freqs->freqs[j], w, geno); for (i = 0; i < geno; i++) data->freqs->freqs[j][i] = (data->freqs->freqs[j][i] * w[i]) / wbar; } } void age_dep_norm_mtable (double * ffreqs, age_dep_params_t * params) { /* this function produces a single mating table that forms the input for recombination () */ /* i is female genotype; j is male genotype; k is male age */ int i,j,k; double norm_denom; double trait; size_t geno = params->age_dep_data->geno; for (i = 0; i < geno; i++) { double norm_mtable[geno]; /* initialize the denominator: */ norm_denom = 0.0; /* find the probability of mating and add it to the denominator */ for (j = 0; j < geno; j++) { /* initialize entry: */ norm_mtable[j] = 0.0; for (k = 0; k < age_max; k++) { trait = age_dep_trait (k, j, params->by); norm_mtable[j] += age_dep_pmate (trait, i, params->bp, params->ba) * (params->freqs->freqs)[k][j]; } norm_denom += norm_mtable[j]; } /* now calculate entry (i,j) */ for (j = 0; j < geno; j++) params->age_dep_data->mtable[i][j] = (ffreqs[i] * norm_mtable[j]) / norm_denom; } } My current suspicion is the array newfreqs: I can't memmove, memcpy or assign a stack variable then hope it will persist, can I? rec_mating() returns double *.

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  • What would be a good opensource software for graphing circles, circular regions, and regions bounded by curves and/or arcs?

    - by Michael Dykes
    Hullo all. I have just started s job with Chegg, and my 1st assignment has me writign solutions for Stewart's Essential Calculus. I am dealing with the chapter on multiple integration, and need a good open-source software that I can easily use to draw regions (domains) that would require multiple integrals: i.e. circular regions, portions of circles, regions bounded by curves and/or arcs, and at some point 3D pictures. In most of these cases, I am not working with an exact equation or perhaps need to draw the region bounded by r (radius) between 1 and 2, and the angle theta bounded between pi/4 and 3 pi/4. I am not too terribly familiar with programs like Corel Draw, but the documents I have from this company suggest Corel Draw. So I think I am looking for an open-source free program like Corel Draw or something similar. Any additional suggestions would also be appreciated. I know I can do most, if not all of this using TikZ, but the learning curve is a bit steep, and at the moment I an on a time constraint. Thanks.

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  • Observing MVC, can/should the Model be instantiated in the ViewController? Or where?

    - by user19410
    I'm writing an experimental iPhone app to learn about the MVC paradigm. I instantiate my Model class in the ViewController class. Is this stupid? I'm asking because storing the id of the Model class, and using it works where it's initialized, but referring to it later (in response to an interface action) crashes. Seemingly, the pointer address of my Model class instance changes, but how can that be? The code in question: @interface Soundcheck_Tone_GeneratorViewController : UIViewController { IBOutlet UIPickerView * frequencyWheel; @public Sinewave_Generation * sineGenerator; } @property(nonatomic,retain) Sinewave_Generation * sineGenerator; @end @implementation Soundcheck_Tone_GeneratorViewController @synthesize sineGenerator; - (void)viewDidLoad { [super viewDidLoad]; [self setSineGenerator:[[Sinewave_Generation alloc] initWithFrequency:20.0]]; // using reference -> fine } // pickerView handling is omitted here... - (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { [[self sineGenerator] setFrequency:20.0]; // using reference -> crash } @end // the Sinewave_Generation class... only to be thorough. Works fine so far. @interface Sinewave_Generation : NSObject { AudioComponentInstance toneUnit; @public double frequency,theta; } @property double frequency; - (Sinewave_Generation *) initWithFrequency: (int) f; @end @implementation Sinewave_Generation @synthesize frequency; - (Sinewave_Generation *) initWithFrequency: (int) f { self = [super init]; if ( self ) { [self setFrequency: f]; } return self; } @end

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  • Object as an array

    - by owca
    I need to create class Dog and PurebredDog extending Dog. Problem is that Dog can be at once single object and array of objects (Dogs and PurebreedDogs : Dog pack[]={new Dog(76589,"As","black",18, "Ann","Kowalsky"), new PurebreedDog(45321,"Labrador","Elf","black",25, "Angus","Mati","Barbara","Smith"), new Dog(102467,"Gamma","brown",89, "Josh","Coke"), new PurebreedDog(9678,"York","Theta","brown",8, "Emka","Figaro","Alice","Cat")}; for(int i=0; i < pack.length; i++) System.out.println(pack[i]+"\n\n"); How to write proper constructor for Dog ?

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  • How do you calculate the reflex angle given to vectors in 3D space?

    - by Reimund
    I want to calculate the angle between two vectors a and b. Lets assume these are at the origin. This can be done with theta = arccos(a . b / |a| * |b|) However arccos gives you the angle in [0, pi], i.e. it will never give you an angle greater than 180 degrees, which is what I want. So how do you find out when the vectors have gone past the 180 degree mark? In 2D I would simply let the sign of the y-component on one of the vectors determine what quadrant the vector is in. But what is the easiest way to do it in 3D?

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  • Relative Position in PHP between 2 points (Lat/Long)

    - by Brian H
    I have a database of airports with Latitude and Longitude for each point. I want to run a PHP script to find all airports that are nearby a given airport, with their distance and relative direction. I.e. for Airport KLDJ (40-37-02.810N 074-14-40.539W) Airport Nearby KJFK - John F Kennedy Airport (21.2 nm NE) (40-38-23.104N 073-46-44.132W) I have used code from http://www.movable-type.co.uk/scripts/latlong.html to find distance, and tried to use it to find bearing, which might not be right. //BEARING RHUMB LINE $phi = log(tan($lat2/2+pi/4)/tan($lat1/2+pi/4)); $distance['bearing'] = (rad2deg(atan2($theta, $phi)) +180) % 360; I basically want to run all points through this script and find the distance, which I have already, but then the direction. (i.e. N, S, W, E, NW, SW, NE, SE)

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  • How to efficiently replace characters in XML document in Java?

    - by Pregzt
    I'm looking for a neat and efficient way to replace characters in XML document. There is a replacement table defined for almost 12.000 UTF-8 characters, most of them are to be replaced by single characters, but some must be replaced by two or even three characters (e.g. Greek theta should become TH). The documents can be bulky (100MB+). How to do it in Java? I came up with the idea of using XSLT, but I'm not too sure if this is the best option.

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  • How to color a mesh with values at the vertices in WPF 3D?

    - by Christo
    We've got a sphere which we want to display in 3D and color given a fuction that depends on spherical coordinates. The sphere was triangulated using a regular grid in (theta, phi), but this produced a lot of small triangles near the poles. In an attempt to reduce the number triangles at the poles, we've changed out mesh generation to produce more evenly sized triangles over the surface. The first triangulation method had the advantage that we could easily create a texture and drape it over the surface. It seems that in WPF it isn't possible to assign colors to vertices the way one would go about in OpenGL or Direct3D. With the second triangulation method it isn't apparent how to go about generating the texture and setting the texture coordinates, since the vertices aren't aligned to a grid anymore. Maybe it would be possible to create a linear texture containing a color for each vertex, but then how will that effect the coloring? Will it still render smoothly over the triangle surfaces as one would expect by applying per vertex coloring?

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  • Cone-Line Segment Intersection 2D

    - by nophnoph
    Hi everyone, I would like to know is there any way to determine if a cone is intersecting with a (finite)line segment. The cone actually a circle located at P(x,y) with theta degree field of view and radius r. The simple visualization can be found here (sorry i can't post the picture here) I'm trying to do it in C# but I don't have any idea how to that, so for now this is what I'm doing : Check if the line segment is intersecting with the circle If the line segment is intersecting with the circle then I check every single point in the line segment using a function I found here. But I don't think this is the best way to do it. Does anyone have an idea? For additional info, I need this function to make some kind of simple vision simulator. Thanks in advance :)

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  • How to use C# nested structures to access tree of data

    - by zotty
    I'm importing some XML to C#, and want to be able to access data from the XML in the form of what I think is a nested structure. (I may be wrong!) What I have in my XML is in the following form: <hardwareSettings initial="true> <cameraSettings width="1024" height="768" depth="8" /> <tiltSettings theta="35" rho="90"> </hardwareSettings> I can import each setting alright, so I have them all in individual ints, but I would like to be able to access it in the form int x=hardwaresettings.camerasettings.width; int rho=hardwaresettings.tiltsettings.rho; I've tried various arrangements of structs within structs, but I don't seem able to cast a new object (hardwaresettings) that contains the appropriate children (camerasettings.width & tiltsettings.rho). Sorry if I'm not using the right lingo... I'm reading myself in circles here!

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  • A* navigational mesh path finding

    - by theguywholikeslinux
    So I've been making this top down 2D java game in this framework called Greenfoot [1] and I've been working on the AI for the guys you are gonna fight. I want them to be able to move around the world realistically so I soon realized, amongst a couple of other things, I would need some kind of pathfinding. I have made two A* prototypes. One is grid based and then I made one that works with waypoints so now I need to work out a way to get from a 2d "map" of the obstacles/buildings to a graph of nodes that I can make a path from. The actual pathfinding seems fine, just my open and closed lists could use a more efficient data structure, but I'll get to that if and when I need to. I intend to use a navigational mesh for all the reasons out lined in this post on ai-blog.net [2]. However, the problem I have faced is that what A* thinks is the shortest path from the polygon centres/edges is not necessarily the shortest path if you travel through any part of the node. To get a better idea you can see the question I asked on stackoverflow [3]. I got a good answer concerning a visibility graph. I have since purchased the book (Computational Geometry: Algorithms and Applications [4]) and read further into the topic, however I am still in favour of a navigational mesh (See "Managing Complexity" [5] from Amit’s Notes about Path-Finding [6]). (As a side note, maybe I could possibly use Theta* to convert multiple waypoints into one straight line if the first and last are not obscured. Or each time I move back check to the waypoint before last to see if I can go straight from that to this) So basically what I want is a navigational mesh where once I have put it through a funnel algorithm (e.g. this one from Digesting Duck [7]) I will get the true shortest path, rather than get one that is the shortest path following node to node only, but not the actual shortest given that you can go through some polygons and skip nodes/edges. Oh and I also want to know how you suggest storing the information concerning the polygons. For the waypoint prototype example I made I just had each node as an object and stored a list of all the other nodes you could travel to from that node, I'm guessing that won't work with polygons? and how to I tell if a polygon is open/traversable or if it is a solid object? How do I store which nodes make up the polygon? Finally, for the record: I do want to programme this by myself from scratch even though there are already other solutions available and I don't intend to be (re) using this code in anything other than this game so it does not matter that it will inevitably be poor quality. http://greenfoot.org http://www.ai-blog.net/archives/000152.html http://stackoverflow.com/q/7585515/ http://www.cs.uu.nl/geobook/ http://theory.stanford.edu/~amitp/GameProgramming/MapRepresentations.html http://theory.stanford.edu/~amitp/GameProgramming/ http://digestingduck.blogspot.com/2010/03/simple-stupid-funnel-algorithm.html

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  • 2D camera perspective projection from 3D coordinates -- HOW?

    - by Jack
    I am developing a camera for a 2D game with a top-down view that has depth. It's almost a 3D camera. Basically, every object has a Z even though it is in 2D, and similarly to parallax layers their position, scale and rotation speed vary based on their Z. I guess this would be a perspective projection. But I am having trouble converting the objects' 3D coordinates into the 2D space of the screen so that everything has correct perspective and scale. I never learned matrices though I did dig the topic a bit today. I tried without using matrices thanks to this article but every attempt gave awkward results. I'm using ActionScript 3 and Flash 11+ (Starling), where the screen coordinates work like this: Left-handed coordinates system illustration I can explain further what I did if you want to help me sort out what's wrong, or you can directly tell me how you would do it properly. In case you prefer the former, read on. These are images showing the formulas I used: upload.wikimedia.org/math/1/c/8/1c89722619b756d05adb4ea38ee6f62b.png upload.wikimedia.org/math/d/4/0/d4069770c68cb8f1aa4b5cfc57e81bc3.png (Sorry new users can't post images, but both are from the wikipedia article linked above, section "Perspective projection". That's where you'll find what all variables mean, too) The long formula is greatly simplified because I believe a normal top-down 2D camera has no X/Y/Z rotation values (correct ?). Then it becomes d = a - c. Still, I can't get it to work. Maybe you could explain what numbers I should put in a(xyz), c(xyz), theta(xyz), and particularly, e(xyz) ? I don't quite get how e is different than c in my case. c.z is also an issue to me. If the Z of the camera's target object is 0, should the camera's Z be something like -600 ? ( = focal length of 600) Whatever I do, it's wrong. I only got it to work when I used arbitrary calculations that "looked" right, like most cameras with parallax layers seem to do, but that's fake! ;) If I want objects to travel between Z layers I might as well do it right. :) Thanks a lot for your help!

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  • Move a sphere along the swipe?

    - by gameOne
    I am trying to get a sphere curl based on the swipe. I know this has been asked many times, but still it's yearning to be answered. I have managed to add force on the direction of the swipe and it works near perfect. I also have all the swipe positions stored in a list. Now I would like to know how can the curl be achieved. I believe the the curve in the swipe can be calculated by the Vector dot product If theta is 0, then there is no need to add the swipe. If it is not, then add the curl. Maybe this condition is redundant if I managed to find how to curl the sphere along the swipe position The code that adds the force to sphere based on the swipe direction is as below: using UnityEngine; using System.Collections; using System.Collections.Generic; public class SwipeControl : MonoBehaviour { //First establish some variables private Vector3 fp; //First finger position private Vector3 lp; //Last finger position private Vector3 ip; //some intermediate finger position private float dragDistance; //Distance needed for a swipe to register public float power; private Vector3 footballPos; private bool canShoot = true; private float factor = 40f; private List<Vector3> touchPositions = new List<Vector3>(); void Start(){ dragDistance = Screen.height*20/100; Physics.gravity = new Vector3(0, -20, 0); footballPos = transform.position; } // Update is called once per frame void Update() { //Examine the touch inputs foreach (Touch touch in Input.touches) { /*if (touch.phase == TouchPhase.Began) { fp = touch.position; lp = touch.position; }*/ if (touch.phase == TouchPhase.Moved) { touchPositions.Add(touch.position); } if (touch.phase == TouchPhase.Ended) { fp = touchPositions[0]; lp = touchPositions[touchPositions.Count-1]; ip = touchPositions[touchPositions.Count/2]; //First check if it's actually a drag if (Mathf.Abs(lp.x - fp.x) > dragDistance || Mathf.Abs(lp.y - fp.y) > dragDistance) { //It's a drag //Now check what direction the drag was //First check which axis if (Mathf.Abs(lp.x - fp.x) > Mathf.Abs(lp.y - fp.y)) { //If the horizontal movement is greater than the vertical movement... if ((lp.x>fp.x) && canShoot) //If the movement was to the right) { //Right move float x = (lp.x - fp.x) / Screen.height * factor; rigidbody.AddForce((new Vector3(x,10,16))*power); Debug.Log("right "+(lp.x-fp.x));//MOVE RIGHT CODE HERE canShoot = false; //rigidbody.AddForce((new Vector3((lp.x-fp.x)/30,10,16))*power); StartCoroutine(ReturnBall()); } else { //Left move float x = (lp.x - fp.x) / Screen.height * factor; rigidbody.AddForce((new Vector3(x,10,16))*power); Debug.Log("left "+(lp.x-fp.x));//MOVE LEFT CODE HERE canShoot = false; //rigidbody.AddForce(new Vector3((lp.x-fp.x)/30,10,16)*power); StartCoroutine(ReturnBall()); } } else { //the vertical movement is greater than the horizontal movement if (lp.y>fp.y) //If the movement was up { //Up move float y = (lp.y-fp.y)/Screen.height*factor; float x = (lp.x - fp.x) / Screen.height * factor; rigidbody.AddForce((new Vector3(x,y,16))*power); Debug.Log("up "+(lp.x-fp.x));//MOVE UP CODE HERE canShoot = false; //rigidbody.AddForce(new Vector3((lp.x-fp.x)/30,10,16)*power); StartCoroutine(ReturnBall()); } else { //Down move Debug.Log("down "+lp+" "+fp);//MOVE DOWN CODE HERE } } } else { //It's a tap Debug.Log("none");//TAP CODE HERE } } } } IEnumerator ReturnBall() { yield return new WaitForSeconds(5.0f); rigidbody.velocity = Vector3.zero; rigidbody.angularVelocity = Vector3.zero; transform.position = footballPos; canShoot =true; isKicked = false; } }

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  • Seeking C Union clarity

    - by mustISignUp
    typedef union { float flts[4]; struct { GLfloat r; GLfloat theta; GLfloat phi; GLfloat w; }; struct { GLfloat x; GLfloat y; GLfloat z; GLfloat w; }; } FltVector; Ok, so i think i get how to use this, (or, this is how i have seen it used) ie. FltVector fltVec1 = {{1.0f, 1.0f, 1.0f, 1.0f}}; float aaa = fltVec1.x; etc. But i'm not really groking how much storage has been declared by the union (4 floats? 8 floats? 12 floats?), how? and why? Also why two sets of curly braces when using FltVector {{}}? Any pointers much appreciated (sorry for the pun)

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