vector calculus?:eek:
I have a vertex’s position, and its normal direction. How can I find the “opposite” normal direction of this vertex from these? Seems like this should be simple, but it’s driving me nuts!
It’s been awhile, but if your vector is, say, [1,1,1] (XYZ) the opposite vector would be [-1,-1,-1].
See this vector as a line pointing from [0,0,0] to [1,1,1]. The opposite vector would go from [1,1,1] to [0,0,0], can you see it? Draw it out on paper, it helps a lot.
The values have to go to 0 again: 1-1=0. So just use the negative value.
[1,-5,0] >> [-1,5,0]
[3.1416,-2.7183,1.4142] >> [-3.1416,2.7183,-1.4142]
Hope this helps.
- Rens
Yes Rens is right, to write it in an easy way you could just put a – before your Point3 like so:
-[1,1,1]
CML
Too easy!
So I will just use “xyz – (xyz + xyz)”, to get the opposite direction! I feel kinda dumb now!
Thanks Rens!
You’re welcome,
So I will just use “xyz – (xyz + xyz)”, to get the opposite direction!
Or, like Rivendale said, just use “-xyz” instead of “xyz – (xyz + xyz)”.
- R