Area Light Source

OpenGL OpenGL: Advanced Coding
1

I have looked through the documentation and haven’t found any mention of area light sources.:frowning:

Does anyone know how to implement an area light source so that you get the umbra and penumbra instead of the sharp shadows that you get with point and spotlight sources.

Thanks for your help,
Steve

2

I don’t know what do you mean by area light, however, to avoid sharp shadows there is no other way than dividing one large plane or surface into many small pieces of subsurfaces and using spot light. The problem is that OGL calculate color components only for the primitives that define a surface. The color components of the in-between points are calculated using interpolation methods.

3

Area lights are not in OpenGL.

Neither is any shadowing except the kind of shadowing that happens when a triangle is facing away from a light source.

On the NVIDIA developer site there is a demo that shows how to do shadows using shadow volumes and the stencil buffer. They have a version of it that does soft shadows.

The demos are at www.nvidia.com/developer

j