View Full Version : How to calculate Normal for 3D Triangle

vinothrajendran4

11-16-2016, 06:58 AM

Hi Everyone,

I am new to openGL, I would like to know the calculation involved in finding the normal for triangle with four faces in 3D.....

Silence

11-16-2016, 07:31 AM

A triangle with 4 faces ?

If you have a triangle ABC, then the normal of it is the cross product of the vectors AB and AC.

vinothrajendran4

11-16-2016, 09:22 PM

thank you Silence for your reply.

But i am looking for normal calculation involved in Egypt Pyramid (which has 4 faces and a polygon base)....

Silence

11-18-2016, 12:08 AM

This is exactly what I said. Do that for each vertex of each of your triangles. For pyramids, normals at each vertex are the normals of the face they belong to.

__bob__

11-21-2016, 06:21 AM

A triangle with 4 faces ?

If you have a triangle ABC, then the normal of it is the cross product of the vectors AB and AC.

And dont forget to normalize the result!

Silence

11-21-2016, 07:28 AM

And dont forget to normalize the result!

Right ! Otherwise it won't be a normal.

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