[away3d] Re: Simplest way to draw a plane given 3 points

[Li]

Well, first of all you would need to identify the vectors with something
like this (I wont be testing this, its just some suggestions):

Define the 3 points...

                var p0:Number3D = new Number3D(0, 0, 0);
                var p1:Number3D = new Number3D(100, 0, 0);
                var p2:Number3D = new Number3D(0, 100, 0);

Identify the vectors between them...

                var v0:Number3D = new Number3D();
                v0.sub(p1, p0);
                var v1:Number3D = new Number3D();
                v1.sub(p2, p0);

The position of the plane should be the mid point...

                var vMid:Number3D = new Number3D((v0.x + v1.x)/2, (v0.y +
v1.y)/2, (v0.z + v1.z)/2);

Now the orientation. The normal can be used to project a point facing the
plane...

                var vNorm:Number3D = v0.cross(v0, v1);
                var vLook:Number3D = new Number3D();
                vLook.add(vMid, vNorm);

And apply...

                var plane:Plane = new Plane();
                plane.width = v0.modulo;
                plane.height = v1.modulo;
                plane.position = vMid;
                plane.lookAt(vLook);