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Manipulating Object Normals

Object normals are vectors that are perpendicular to the surface. They are used in lighting calculations to determine how the light should bounce off a surface at any particular point. By manipulating them, you can control the diffuse and specular light contributions.

To Manipulate Object Normals

1.   Select 3D > Modify > Normals to insert a Normals node anywhere after the 3D object whose lighting you want to adjust.
2.   Connect a Camera, Axis, or light node to the Normals node’s lookat input.
3.   In the Normals controls, open the action dropdown menu and select:

unchanged to make no changes.

set to assign the normals value to the normal x, y, and z fields.

build to rebuild each normal based on the surrounding vertices. Adjust the threshold angle slider to determine the break angle where two faces no longer constitute a smooth surface. An angle of 0 means all faces are flat, whereas 180 means all faces are smooth. A good average setting is 60.

lookat to point all normals towards the Normals node’s lookat input.

delete to remove the named attribute from the object. For example, if you remove the N attribute, the object has no normals.