Request Info on Normal Camera

[ggray7]

Could anyone explain Normal Camera as found in the samplerInfo Utility node. Specifically how this differs from the actual normal of the geometry being shaded. If these are not the same, how can one access the normal of the geo being shaded(I'm assuming in world space is what I really want here)

Thanx for any info you can provide
~Garret Gray

this message is posted in both the Rendering Forum as well as the MEL since it deals with issues of both and in the hope of reaching more forum readers

[tbriggs01]

My first answer disappeared so I'll try again.

Normal camera is the surface normal in camera space. Put another way it is the difference between the angle of the surface normal and the camera view vector, normalized and inverted. This gives you a value of 0 when the surface normal is perpendicular to the camera view, and 1 when it points directly at the camera.

In theory there is no difference between theory and practice. In practice they are very different

[ggray7]

Thanx for the reply t, I wasn't sure I'd get anything on this.

so my next question is how can I access the surface normal in world space or object space?
Relative to the view plane is great for some things, but what if I want to test the normal compared to say just the Y axis? I am aware that some 3d textures, such as snow do this, but I'd like to know how to just get that normal in world so I'm free to do anything with it.

Thanx for an info you can provide
~Garret

[tbriggs01]

Every shader has a normal camera output, look there. If there have been no bump functions in the shader that should give you the surface normal.

In theory there is no difference between theory and practice. In practice they are very different