I've been having some troubles lately with lighting. I have found a source on google which is working pretty good on the example. However, when I try to implement it to my current project, I am getting some very weird bugs. The main one is that my textures are "mixed up" when I only activate the ambient light, which means that a model gets the texture of another one .
I am using the same effect for every meshes of my models. I guess this could be the problem, but I don't really know how to "reset" an effect for a new model. Is it possible?
Here is my shader:
float4x4 WVP;
float4x4 WVP;
float3x3 World;
float3 Ke;
float3 Ka;
float3 Kd;
float3 Ks;
float specularPower;
float3 globalAmbient;
float3 lightColor;
float3 eyePosition;
float3 lightDirection;
float3 lightPosition;
float spotPower;
texture2D Texture;
sampler2D texSampler = sampler_state
{
Texture = <Texture>;
MinFilter = anisotropic;
MagFilter = anisotropic;
MipFilter = linear;
MaxAnisotropy = 16;
};
struct VertexShaderInput
{
float4 Position : POSITION0;
float2 Texture : TEXCOORD0;
float3 Normal : NORMAL0;
};
struct VertexShaderOutput
{
float4 Position : POSITION0;
float2 Texture : TEXCOORD0;
float3 PositionO: TEXCOORD1;
float3 Normal : NORMAL0;
};
VertexShaderOutput VertexShaderFunction(VertexShaderInput input)
{
VertexShaderOutput output;
output.Position = mul(input.Position, WVP);
output.Normal = input.Normal;
output.PositionO = input.Position.xyz;
output.Texture = input.Texture;
return output;
}
float4 PSAmbient(VertexShaderOutput input) : COLOR0
{
return float4(Ka*globalAmbient + Ke,1) * tex2D(texSampler,input.Texture);
}
float4 PSDirectionalLight(VertexShaderOutput input) : COLOR0
{
//Difuze
float3 L = normalize(-lightDirection);
float diffuseLight = max(dot(input.Normal,L), 0);
float3 diffuse = Kd*lightColor*diffuseLight;
//Specular
float3 V = normalize(eyePosition - input.PositionO);
float3 H = normalize(L + V);
float specularLight = pow(max(dot(input.Normal,H),0),specularPower);
if(diffuseLight<=0) specularLight=0;
float3 specular = Ks * lightColor * specularLight;
//sum all light components
float3 light = diffuse + specular;
return float4(light,1) * tex2D(texSampler,input.Texture);
}
technique MultiPassLight
{
pass Ambient
{
VertexShader = compile vs_3_0 VertexShaderFunction();
PixelShader = compile ps_3_0 PSAmbient();
}
pass Directional
{
PixelShader = compile ps_3_0 PSDirectionalLight();
}
}
And here is how I actually apply my effects:
public void ApplyLights(ModelMesh mesh, Matrix world,
Texture2D modelTexture, Camera camera, Effect effect,
GraphicsDevice graphicsDevice)
{
graphicsDevice.BlendState = BlendState.Opaque;
effect.CurrentTechnique.Passes["Ambient"].Apply();
foreach (ModelMeshPart part in mesh.MeshParts)
{
graphicsDevice.SetVertexBuffer(part.VertexBuffer);
graphicsDevice.Indices = part.IndexBuffer;
// Texturing
graphicsDevice.BlendState = BlendState.AlphaBlend;
if (modelTexture != null)
{
effect.Parameters["Texture"].SetValue(
modelTexture
);
}
graphicsDevice.DrawIndexedPrimitives(
PrimitiveType.TriangleList,
part.VertexOffset,
0,
part.NumVertices,
part.StartIndex,
part.PrimitiveCount
);
// Applying our shader to all the mesh parts
effect.Parameters["WVP"].SetValue(
world *
camera.View *
camera.Projection
);
effect.Parameters["World"].SetValue(world);
effect.Parameters["eyePosition"].SetValue(
camera.Position
);
graphicsDevice.BlendState = BlendState.Additive;
// Drawing lights
foreach (DirectionalLight light in DirectionalLights)
{
effect.Parameters["lightColor"].SetValue(light.Color.ToVector3());
effect.Parameters["lightDirection"].SetValue(light.Direction);
// Applying changes and drawing them
effect.CurrentTechnique.Passes["Directional"].Apply();
graphicsDevice.DrawIndexedPrimitives(
PrimitiveType.TriangleList,
part.VertexOffset,
0,
part.NumVertices,
part.StartIndex,
part.PrimitiveCount
);
}
}
I am also applying this when loading the effect:
effect.Parameters["lightColor"].SetValue(Color.White.ToVector3());
effect.Parameters["globalAmbient"].SetValue(Color.White.ToVector3());
effect.Parameters["Ke"].SetValue(0.0f);
effect.Parameters["Ka"].SetValue(0.01f);
effect.Parameters["Kd"].SetValue(1.0f);
effect.Parameters["Ks"].SetValue(0.3f);
effect.Parameters["specularPower"].SetValue(100);
Thank you very much
UPDATE:
I tried to load an effect for each model when drawing, but it doesn't seem to have changed anything. I suppose it is because XNA detects that the effect has already been loaded before and doesn't want to load a new one. Any idea why?
