Thanks, Michael. :)
On Tue, Nov 23, 2010 at 12:57 AM, Michael Iv <[email protected]> wrote:
> So here it is guys ,after several hours the last night and some more like
> these a few couples of months ago i finaly manages to write a correct code
> to perform Ray-Triangle intersection test using ray.getIntersect() ,method.I
> think it is pointless to explain why you would wish to perform such kind of
> test ( especially for those who develop FPS games) .So here is how this
> should be done(for any question on implementation you van ask me):
>
> private function RayFaceTest():Vector3D{
> var intersectVector:Vector3D;
> var ray:Ray=new Ray();
>
> for(var i:int=0;i<_objB.faces.length;++i){
> var
> p0:Vector3D=_objB.sceneTransform.transformVector(_objB.faces[i].vertices[0].position);
> var
> p1:Vector3D=_objB.sceneTransform.transformVector(_objB.faces[i].vertices[1].position);
> var
> p2:Vector3D=_objB.sceneTransform.transformVector(_objB.faces[i].vertices[2].position);
>
> ray.orig=_objA.position;
> var dd:Vector3D=new Vector3D(0,400,0);
> var dird:Vector3D=_objA.transform.transformVector(dd);
>
> ray.dir=dird;
> rayDebug(ray.orig,ray.dir);
>
> intersectVector=ray.getIntersect(ray.orig,ray.dir,p0,p1,p2);
>
> if(intersectVector){
> break;
> }
>
> }
>
> return intersectVector;
> }
>
> Explanation:
> _objA and _objB are two spheres which have the same Z position. _objA is
> movable by keyboard input.We draw a ray from the center of sphere _objA in
> the direction of its local Y with the arbitrary length ( I set to 400).So
> basically when you rotate _objA around Z the ray direction transforms
> according to local _objA Y direction.We test the ray hits against the
> triangles of _objB sphere. Notice that right after for loop start we convert
> each face 3 vertices coords from obj local space into scene spaceNot doing
> so you will never get intersection(actually this was my pitfall ).Then we
> cast the ray passing into getIntersect() ray origin,ray direction vectors
> ,and 3 vertex vectors for the currently tested triangle.
> If the intersection occurs intersectVector returns the coords of the hit
> otherwise it is null.If it is not null we break fro the loop in order to
> return the hit to the function and start the iteration again.This is it .I
> hope it was usefull . :))
>
> --
> Michael Ivanov ,Programmer
> Neurotech Solutions Ltd.
> Flex|Air |3D|Unity|
> www.neurotechresearch.com
> http://blog.alladvanced.net
> http://www.meetup.com/GO3D-Games-Opensource-3D/
> Tel:054-4962254
> [email protected]
> [email protected]
>
>
--
Aji Pamungkas
