# Search Results

• ### XNA: Camera's Rotation and Translation matrices seem to interfere with each other

##### - by Danjen
I've been following the guide here for how to create a custom 2D camera in XNA. It works great, I've implemented it before, but for some reason, the matrix math is throwing me off. public sealed class Camera2D { public Vector2 Origin { get; set; } public Vector2 Position { get; set; } public float Scale { get; set; } public float Rotation { get; set; } } It might be easier to just show you a picture of my problem: http://i.imgur.com/H1l6LEx.png What I want to do is allow the camera to pivot around any given point. Right now, I have the rotations mapped to my shoulder buttons on a gamepad, and if I press them, it should rotate around the point the camera is currently looking at. Then, I use the left stick to move the camera around. The problem is that after it's been rotated, pressing "up" results in it being used relative to the rotation, creating the image above. I understand that matrices have to be applied in a certain order, and that I have to offset the thing to be rotated around the world origin and move it back, but it just won't work! public Matrix GetTransformationMatrix() { Matrix mRotate = Matrix.Identity * Matrix.CreateTranslation(-Origin.X, -Origin.Y, 0.00f) * // Move origin to world center Matrix.CreateRotationZ(MathHelper.ToRadians(Rotation)) * // Apply rotation Matrix.CreateTranslation(+Origin.X, +Origin.Y, 0.00f); // Undo the move operation Matrix mTranslate = Matrix.Identity * Matrix.CreateTranslation(-Position.X, Position.Y, 0.00f); // Apply the actual translation return mRotate * mTranslate; } So to recap, it seems I can have it rotate around an arbitrary point and lose the ability to have "up" move the camera straight up, or I can rotate it around the world origin and have the camera move properly, but not both.

• ### Map Generation Algorithms for Minecraft Clone

##### - by Danjen
I'm making a Minecraft clone for the sake of it (with some inspriation from Dwarf Fortress) and had a few questions about the way the world generation is handled. Things I want it to cover: Biomes such as hills, mountains, forests, etc. Caves/caverns/tunnels Procedural (so it stretches to infinity... is wrap-around a possibility?) Breaking the map into smaller chunks Moddable (ie, new terrain types) Multiplayer compatible In particular, I've seen things such as Perlin Noise, Heightmaps, and Marching Cubes thrown around. These are like different tools to use, but I don't know when or why I would use them. Are there any other techniques that are useful for map generation? I realize this is borderline subjective and open-ended, but I am looking for some more insight into the processes involved.