unity shit

Instead of getting data back from the GPU buffer, we're gonna use this code- Graphics.DrawMeshInstancedIndirect(boidMesh, 0, boidMaterial, bounds, argsBuffer, 0); - to draw instances of a mesh. Note the argsBuffer - this is a new type of buffer, containing arguments. It is defined  in the C# script and we're only initialising the first 2 entries of the array that we fill the argsBuffer with. It can actually hold a lot more information, but for this example, we only provide it with the index of the mesh and the number of them we want to draw. Argument Buffers seem to be very specific to this type of instanced mesh drawing in Unity. It doesn't seem easy to find information about them...  The compute shader and frag/vert shader are not directly concerned with the argument buffer, it seems that the code above is the only actual reference to the argsBuffer! The compute shader only updates the position/direction of the boids. The frag/vert shader (which is actually a surface shad...

This is more or less the same as the last wall of code. However this time, we are using the Graphics draw to draw a quad, which consists of Four points, Two triangles. We need to adjust our buffer and create a new struct for this, as well as initialise our arrays in a specific way to ensure the quads are facing the correct direction.   As mentioned, our new Struct - Vertex stores a position, UV value and life. We're going to use the Compute Shader to calculate the postion of each particle-  but then draw a quad at that position. We set the specific values for the vertices in the compute shader too. (the UVs don't change for each quad, so we set that value in the C# script)     //Triangle 1 - bot left, top left, top right     vertexBuffer[index].position.x = p.position.x - halfSize;     vertexBuffer[index].position.y = p.position.y - halfSize;     vertexBuffer[index].position.z = p.position.z;     vertex...

 Use case - get the GPU to calculate a bunch of X,Y,Z coordinates for an arbitrary number of instanced prefabs in Unity.  On the Unity C# side, we need : To specify a compute shader, a handle for the compute shader, a buffer that we'll be writing to in the shader, a prefab, the number of prefabs we want, an array for the instanced prefabs, an array for the coordinate data. Any extra variables we want to pass over, eg time. On the compute shader side we need : To specify a read-write buffer, instead of a texture that we created in the previous post. The buffer will be of float3 type, which is how HLSL calls a vector3. That's actually it... Here's the Compute Shader code - #pragma kernel boxMove RWStructuredBuffer<float3> yesBlad; float time; [numthreads(64,1,1)] void boxMove (uint3 id : SV_DispatchThreadID) {     float xpos = (float)id.x;     float ypos = sin(id.x+time)*50;     float zpos = cos(id.x +time)* 50;    ...