GLSL built-in function
textureCubeLod()
Samples a cube map at an explicit mip level in the vertex stage.
Demo version: GLSL ES 1.00 / WebGL 1Demo stage: Vertex
Syntax
vec4 textureCubeLod(samplerCube sampler, vec3 direction, float lod)Parameters
- sampler
- Bound fixture texture
- direction
- Input declared in the signature; match its type and dimensions
- lod
- Mip level; zero is full resolution
Return value
A vec4 from the cube map at the given direction and explicit mip level, evaluated in the vertex stage here.
Live example
Edit the code and the preview updates as you type.
What textureCubeLod does
Samples a cube map at an explicit mip level in the vertex stage.
Read the preview
textureCubeLod evaluates normalize(vec3(x,y,0.7)) at vertices, not at every fragment. Change 0.7 to 2.0 in the Vertex tab so all corner samples select +Z instead of side faces.
Core call
textureCubeLod(u_cube,normalize(vec3(x,y,0.7)),u_parameter*7.0).rgb;
Vertex-sampled colors are interpolated and are not identical to per-fragment lookup.
Experiment
Set the Vertex call's u_parameter*7.0 to 6.0. It reads a coarse cube-map mip and interpolates the corner colors; face lettering will not be reconstructed between vertices.