Hello Erik,
Erik Podetti wrote:
> Hi everybody.
> I would like to know if it would be possible to extract or save in any
> way the precomputed gl_NormalMatrix matrix from a shader. As I'm
> implementig a deferred shader I saved normals in world coordinate and I
> need to transform them in eye-space (mgr->camera point of view) inside a
> PolygonForeground shader (where the gl_NormalMatrix is obviously
> incoherent).
as Marcus already said, the gl_NormalMatrix is the transpose of the
inverse of the gl_ModelViewMatrix. It transforms normals from object to
eye space. You are saying that you store normals in world coordinates,
so what you need is the inverse transpose of the viewing matrix, to
transform the normals into eye space.
You get the viewing matrix from Camera::getViewing().
Hope it helps,
Carsten
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