Lighting on Objects
Author
I'll read up on it. Can you point me to some resources? The problem you described is exactly my problem--can you tell me how to set the normals?
http://www.lighthouse3d.com/opengl/terrain/index.php3?normals
I didn't spend much time searching for this, but it seems to be a short, clear guide to calculating normals for a polygon. You'll need to do a cross product to find the perpendicular, then normalize it (set it to length 1) for use in OpenGL.
http://www.glprogramming.com/red/chapter02.html#name5
Here's how the redbook says to declare normals. Their syntax here is a little confusing, but more simply: your typical command will be void glNormal3f(x, y, z);
You call this before each vertex, or just before each polygon for a flat polygon. In the case of faceted gems, the sides are flat and will have 1 normal per polygon, but for smooth objects you supply a normal per vertex, which is interpolated across the polygon and makes it look smoother.
I didn't spend much time searching for this, but it seems to be a short, clear guide to calculating normals for a polygon. You'll need to do a cross product to find the perpendicular, then normalize it (set it to length 1) for use in OpenGL.
http://www.glprogramming.com/red/chapter02.html#name5
Here's how the redbook says to declare normals. Their syntax here is a little confusing, but more simply: your typical command will be void glNormal3f(x, y, z);
You call this before each vertex, or just before each polygon for a flat polygon. In the case of faceted gems, the sides are flat and will have 1 normal per polygon, but for smooth objects you supply a normal per vertex, which is interpolated across the polygon and makes it look smoother.
You set the normal of a vertex with glNormal3d(), like so:
glNormal3d(0.0,0.0,1.0);
glVertex3d(123.0,123.0,123.0);
This Normal points in the z direction. The normal should be normalized for the lighting calculations to work as they should.
More on OpenGL lighting.
glNormal3d(0.0,0.0,1.0);
glVertex3d(123.0,123.0,123.0);
This Normal points in the z direction. The normal should be normalized for the lighting calculations to work as they should.
More on OpenGL lighting.
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