OpenGL - rendering to 3D Texture has no effect on texture - c++

Question

I am trying to splat vertex information into a 3D Texture.
Corresponding C++ code:
GLuint color_tex;
GLuint fb;
glGenTextures(1, &color_tex);
glBindTexture(GL_TEXTURE_3D, color_tex);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT);
glTexImage3D(GL_TEXTURE_3D, 0, GL_R32UI, 32, 32, 32, 0, GL_RED_INTEGER, GL_UNSIGNED_INT, NULL);
//-------------------------
glGenFramebuffers(1, &fb);
glBindFramebuffer(GL_FRAMEBUFFER, fb);
//Attach one of the faces of the Cubemap texture to this FBO
glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, color_tex, 0);
//-------------------------
//Does the GPU support current FBO configuration?
GLenum status;
status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
switch(status)
{
case GL_FRAMEBUFFER_COMPLETE:
std::cout << "good" << std::endl;
default:
break;
}
//-------------------------
glClearColor(0,0,0,0);
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(splat_vertex_ids);
glBindVertexArray( mVAO );
glDrawArrays(mPrimitiveType, 0, mDrawSize);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
GLuint content[32*32*32];
glBindTexture(GL_TEXTURE_3D, color_tex);
glGetTexImage(GL_TEXTURE_3D, 0, GL_RED_INTEGER, GL_UNSIGNED_INT, &content);
for(int i = 0; i< 32*32*32; ++i)
if(content[i] != 0)
std::cout << content[i] << std::endl;
I read back the content to check if anything was rendered, but the texture only contains 0's.
My first thought was, that my shaders don't work correctly, so I replaced them by this :
Geometry Shader:
#version 330
layout(points) in;
layout(points, max_vertices = 1) out;
in vec3[] vPosition;
out vec2 oTexCoord;
void main(void)
{
oTexCoord = vec2(0.2);
gl_Position = vec4(0.2,0.2, 0.2,1);
gl_Layer = 0;
EmitVertex();
EndPrimitive();
}
Vertex Shader:
#version 330
layout(location = 0)in vec3 aPosition;
uniform vec3 uChunkStart;
uniform float uRes;
out vec3 vPosition;
void main(void)
{
vPosition = aPosition;
}
Fragment Shader:
#version 330
in vec2 oTexCoord;
out uint color;
void main(void)
{
color = 1337u;
}
Don't know whats wrong with this. Shouldn't it create a single dot? My first time doing such a thing.
EDIT: Rendering to a 2D texture also fails