Hello guys! I'm working with a 3D game,and I need to solve the following problem: I have a plane in the 3D space, actualæy it is a triangle... So what i know is the three points of the triangle, lets say I have the points v1 = (1,2,3), v2 = (4,5,6) and v3 = (7,8,9). If I now pick a point within the triangle, and we call the point u = (x,y,z). Now i know the coordinates x and z of the u point, how can I find the coordinate y ?!?

You have the equation of the plane (p is any point on that plane):
p = v1 + s (v2-v1) + t (v3 - v1).

By inserting your point you could solve for s, t and y.

Othe possibility: Take the plane equation of the form (p - v1).n = 0, where n is the normal vector of your plane. by inserting (x, y, z) of your point for p you can solve for y.

Quote:Original post by VolkerG
You have the equation of the plane (p is any point on that plane):
p = v1 + s (v2-v1) + t (v3 - v1).

By inserting your point you could solve for s, t and y.

Othe possibility: Take the plane equation of the form (p - v1).n = 0, where n is the normal vector of your plane. by inserting (x, y, z) of your point for p you can solve for y.

Thanks alot dude, I'll try that!
Btw. Mary christmas and happy new year!!!