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Graphics / Determining world position of the current fragment in a shader
« on: January 22, 2015, 12:59:12 pm »
I am trying to make a lighting fragment shader. For that, I need to know the world position of the fragment in order to determine its distance to the light source (in world units). Should I do it by setting up a varying world coordinates variable in a vertex shader? If so, can SFML provide the model matrix needed to compute the vertex world position like this?:
Or should I compute the vertex world positions in SFML - getting the entity transform, applying it to local vertex coords then passing the results to the vertex shader?
Is this even the correct way to make a per-pixel lighting shader with SFML that would not change output with view/screen transformations?
vec2 world_coords = gl_Vertex * gl_ModelMatrix
Or should I compute the vertex world positions in SFML - getting the entity transform, applying it to local vertex coords then passing the results to the vertex shader?
Is this even the correct way to make a per-pixel lighting shader with SFML that would not change output with view/screen transformations?