I need a simple sample of accessing mipmap levels of a single texture (float) inside a fragment shader. I know that I have to use the bias parameter, but it doesn't work. I created all mipmap levels for a texture 64x64 downto 1x1 with different color settings, but when I try to access another level than 0, with:
col = texture2D( inputTexture, uv, 2.0 );
it doesn't work.
What's the range for the bias parameter?
Do I have to add something in the vertex shader to make mipmap access work in the fragment shader?
Is the mapping for the bias parameter 1.0 -> level 1, 2.0 -> level 2, etc. or something els?