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depth cubemap texture array setup

Started by Yours3!f Aug 16, 2014 at 3:58 PM 2 replies 3.7k views

Original Post

Aug 16, 2014 at 3:58 PM

hi there,

is this the correct way to set up depth cubemap texture arrays? My problem is that nothing is rendered to the textures...

EDIT: I seem to have been able to render 1 face correctly, I still suspect the setup code.

I get no errors or debug output messages.
I suspect that I should somehow enable each face as usual with the cubemaps, but I couldn't find a way to do that...


  GLuint point_shadow_texture;
  glGenTextures(1, &point_shadow_texture);
  glBindTexture(GL_TEXTURE_CUBE_MAP_ARRAY, point_shadow_texture);

  glTexParameteri( GL_TEXTURE_CUBE_MAP_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
  glTexParameteri( GL_TEXTURE_CUBE_MAP_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
  glTexParameteri( GL_TEXTURE_CUBE_MAP_ARRAY, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE );
  glTexParameteri( GL_TEXTURE_CUBE_MAP_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  glTexParameteri( GL_TEXTURE_CUBE_MAP_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
  glTexImage3D( GL_TEXTURE_CUBE_MAP_ARRAY, 0, GL_DEPTH_COMPONENT32, shadow_texture_size.x, shadow_texture_size.y, lights.size() * 6, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, 0 );

  vector<GLuint> point_shadow_fbos;
  point_shadow_fbos.resize( lights.size() );
  glGenFramebuffers( lights.size(), &point_shadow_fbos[0] );

  for( int c = 0; c < lights.size(); ++c )
  {
    glBindFramebuffer( GL_FRAMEBUFFER, point_shadow_fbos[c] );
    glDrawBuffer( GL_NONE );
    glFramebufferTextureLayer( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, point_shadow_texture, 0, c );
    frm.check_fbo_status();
  }

  glBindFramebuffer( GL_FRAMEBUFFER, 0 );

usually I set up non-texture-array depth cubemaps like this:


  GLuint cubemap_tex;
  glGenTextures( 1, &cubemap_tex );
  glBindTexture( GL_TEXTURE_CUBE_MAP, cubemap_tex );

  glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
  glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
  glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE );
  glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
  glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR );

  uvec2 texsize( 1024 );

  for( int c = 0; c < 6; ++c )
    glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_X + c, 0, GL_DEPTH_COMPONENT24, texsize.x, texsize.y, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, 0 );

  GLuint cubemap_fbo;
  glGenFramebuffers( 1, &cubemap_fbo );
  glBindFramebuffer( GL_FRAMEBUFFER, cubemap_fbo );

  //attach depth cubemap to fbo's depth attachment
  glFramebufferTexture( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, cubemap_tex, 0 );

  //no color textures attached
  glDrawBuffer( GL_NONE );

  frm.check_fbo_status();

  //unbind
  glBindFramebuffer( GL_FRAMEBUFFER, 0 );

Best regards,

Yours3!f

Aug 17, 2014 at 10:06 AM

so here's a screenshot, one depth cubemap face actually is getting rendered somehow, and I can use that correctly, but the rest isnt...

http://minus.com/i/tPkoxflyGROM

Yours3!f

Aug 17, 2014 at 12:34 PM

so it seems like if you change the layer to 0..6 then each face of the cubemap DOES render correctly, but not all of them at once.

like this:


glFramebufferTextureLayer( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, point_shadow_texture, 0, 0 );
glFramebufferTextureLayer( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, point_shadow_texture, 0, 1 );
glFramebufferTextureLayer( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, point_shadow_texture, 0, 2 );
...
glFramebufferTextureLayer( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, point_shadow_texture, 0, 6 );

here's the vertex shader I'm using:


#version 430 core

uniform mat4 light_model_mat;

layout(location=0) in vec4 in_vertex;

void main()
{
  gl_Position = light_model_mat * in_vertex;
}

the geometry shader:


#version 430 core

//get me a triangle
layout(triangles) in; 
//3 vertices per triangle, 6 triangles overall
layout(triangle_strip, max_vertices=18) out;

//per face view projection matrices
uniform mat4 cube_viewproj[6];

void main()
{
  //redirect to 6 cubemap faces
  for(gl_Layer = 0; gl_Layer < 6; ++gl_Layer)
  {
    for(int c = 0; c < 3; ++c) //send the triangle through
    {
      gl_Position = cube_viewproj[gl_Layer] * gl_in[c].gl_Position;
      EmitVertex();
    }
    
    EndPrimitive();
  }
}

and the pixel shader:


#version 430 core

out vec4 color;

void main()
{
  color = vec4(1);
}

Yours3!f

Aug 17, 2014 at 12:49 PM

seems like if I just bind the texture as a non-layered texture, then it does get rendered correctly... But then I can't use the other layers... Is this a driver bug? Anyone?


glFramebufferTexture( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, point_shadow_texture, 0 );

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