what is normal in 3d software?

[Ian Jones]

Do you mean what is a normal? A surface normal represents the direction in which a surface is facing. A surface normal is perpendicular to the face which it represents. Ever heard of flipping normals? when you do it to a simple box for example you only see the inward facing surfaces. My explanation isn't very professional.... maybe someone else can help. :)

[rayguo]

thank you very much
but the nomal is relate to a surface's appearance?

[Array]

Originally posted by rayguo
thank you very much
but the nomal is relate to a surface's appearance?

the surface normal has a LOT of influence over the appearance of a surface. most lighting models compare the surface normal to the incidance vector to the light in order to calculate highlights, etc. If you edit the normals, you can fake the appearance of geometry that isnt really there (called bump mapping).

theres another technique called normal mapping which is becoming common in video games. The idea is to take the normals from a high polygon mesh and apply them to a low polygon mesh for rendering in realtime. the results are quite stunning. just look at some doom 3 screenshots.

[rayguo]

hi array
your words can give me greate help!!
i know much more about normal now
thank you agian :)))

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.