Normalize the normal in the fragment shader

[stasm]

The normals are computed in the vertex shader, after which they're interpolated between vertices for each rasterized fragment. This interpolation can change the magnitude of the per-fragment normal, so it's best to normalize normals in the fragment shader.

[xem]

Thanks! I read that's recommended indeed, and I understand what it means mathematically, so I will accept your PR, though i can't figure out what's rhe risk if we don't do it? Slightly deformed shading? Something else? Thanks :)

[stasm]

Good question. My understanding is that you risk having slightly incorrect shading, yes, in particular on fragments far away from any vertex. The nDotL thing in the fragment shader is meant to measure the angle between the fragment's normal and the light direction. dot(a, b) = cos(angle between a and b), but only when a and b are normalized. If they're not, you need to divide by the product of their magnitudes:

[xem]

thanks :D