Archived

This topic is now archived and is closed to further replies.

plane normals n stuff

This topic is 5742 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

Recommended Posts

Well, the search function is down and I can''t find what I''m looking for on the net so I have to ask here. Ok, I have a block, 8 corners and 6 faces (like a dice but with iregular quads). Now I want to find out how to calculate the normal för each face of the block. I know the origin and the corners coordinates. If anyone care to explain or point me to a site where it is explained in plain english (swedish will do as well), that would be nice. Thanks

Share on other sites
So if A,B and C are 3D-coordinates that would be something like this: (A.x*B.x, A.y*B.y, A.z*B.z) * (A.x*C.x, A.y*C.y, A.z*C.z), correct?

Share on other sites
No, AB means the vector (b.x-a.x, b.y-a.y, b.z-a.z) and x denotes the vector product.

Strange notation

Share on other sites
quote:
Original post by Anonymous Poster
No, AB means the vector (b.x-a.x, b.y-a.y, b.z-a.z) and x denotes the vector product.

The cross product actually (If U want the normal).
A x B would be (C):
C.x = A.y*B.z - A.z*B.y
C.y = A.z*B.x - A.x*B.z
C.z = A.x*B.y - A.y*B.x
C is the result vector (the normal); it''s peripendicular to A and B.

I hope I remember it correctly...

p.s. is the normal faces the wrong way swap A and B.

see amir.cfxweb.net

• 11
• 20
• 12
• 10
• 34
• Forum Statistics

• Total Topics
631399
• Total Posts
2999854
×