I’ve been working on a simple voxel raymarcher in OpenGL. I’ve got a pretty crude system of passing the center positions of my voxels to the fragment shader through the use of Buffer Textures. My main problem is rendering them properly. Rendering a single voxel is fast and works well, but I want to render multiple. I couldn’t find much online so I came up with this system:

fragment.glsl

...

float map(in vec3 rayPos)
{
    float result = 0;
    for (int i = 0; i < 81; i+=3)
    {
        vec3 pos = vec3(
            texelFetch(voxelData, i).x, 
            texelFetch(voxelData, i+1).x,
            texelFetch(voxelData, i+2).x
        );

        if (i == 0)
        {
            result = Box(rayPos, vec3(VOXEL_SIZE), pos);
        }
        else
        {
            result = min(Box(rayPos, vec3(VOXEL_SIZE), pos), result);
        }
    }
    return result;
}

...

Of course, there are a LOT of optimizations to be made, but at the moment, I’m trying to draft up the basic systems. This code is responsible for displaying a 3x3x3 grid of voxels. It runs terribly but I can’t figure out why. There is definitely a better way to do this but I don’t know how.