# Line - Triangle Collision and Normals

This topic is 3934 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

Any one have a good link for this? I have read a few sites on this subject, and they use the normal to the plane. I have all the normals of the vertexes, how would I convert this into the normal of the plane? I tried adding up the components, then diving by three. That makes the right vector, but its not normalized right? What is the difference between a normalized normal and a unnormalized one? Isnt it still the same normal, just a different length? Does this affect how it renders(like for lighting)?

##### Share on other sites
You can calculate the triangle normal directly from the vertices, without using their normals. Just do (C-A)x(B-A) for vertices A, B, and C, and then normalize.

##### Share on other sites
well i already have the vertex normals, so i think it would take less time to derive the face normals from the vertex normal right?

##### Share on other sites
Quote:
 Original post by bovinedragonWhat is the difference between a normalized normal and a unnormalized one? Isnt it still the same normal, just a different length? Does this affect how it renders(like for lighting)?

A normalized vector is a unit vector. It's a mathemactical description of a geometry's orientation.

Unnormalized vectors are typically used to describe magnitude/distance AND direction.

1. 1
2. 2
Rutin
23
3. 3
JoeJ
20
4. 4
5. 5

• 28
• 40
• 23
• 13
• 13
• ### Forum Statistics

• Total Topics
631737
• Total Posts
3001945
×