I always work with one normal associate with a polygon, but 3ds format
export one normals for each vertex :blink: I don’t understand, some one
help me ?
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Yes, it’s possible to have a normal for each vertex. This is done for
lighting calculations. If you find the normal to a triangle, you are
finding a “Face Normal”. If you give OpenGL a face normal for lighting,
it will make your object look really flat and not very round. If we find
the normal for each vertex, it makes the smooth lighting look. This also
covers up blocky looking objects and they appear to have more polygons
than they do.
per vertex normals are teh w1n!!!!
Render a sphere with per face normals, then
Render a sphere with per vertex normals
the difference is amazing.
That reminds me how many of the neighbour face value normals should I
use to calculate the per vertex value?
imagine it like this :
you find per-polygon normals for each polygon in your model. obviously
this will result in surfaces that will look very flat when lit as apex
said. the easiest way around this is to average the normals of faces
that share a vertex. you then assign this new averaged normal to the
shared vertex and thus get a different normal for each vertex instead of
one for each face.
result == smoother shading.
How to do
davepermen: a VERY nice example.