ray-triangle edge intersection

How to find out which edge has been intersected by the ray during the
ray-triangle intersection procedure if the ray hits an edge. I think
one cand etermine if the ray has hit an edge based on the barycentric
coordinates -

http://upload.wikimedia.org/wikipedia/commons/f/fa/Barycentric_coordinates_1.png

if any of the 3 barycentric coordinates is 0, then the ray has hit an
edge.

The question is which edge ?

If can make the ray intersect independently against every edge and
find the closest intersection but that seems lengthy. Is there a fast
check ?
.

Relevant Pages

  • Re: ray-triangle edge intersection
    ... ray-triangle intersection procedure if the ray hits an edge. ... one cand etermine if the ray has hit an edge based on the barycentric ... If two of the components are zero, then P is one of the triangle ...
    (comp.graphics.algorithms)
  • Re: Fast hit-testing on a heightfield?
    ... Because it's a heightfield, I can't simply get the position of the mouse pointer transformed onto the plane as the mouse might in theory be intersecting many triangles. ... Testing all of the triangles in the heightfield would be major overkill, you should only need to test against a limited number of triangles that cross the ray under the cursor. ... You may further optimize this by testing against the heightmap first to determine areas of possible intersection, to which can avoid more costly ray vs. triangle tests in areas where there is no possible intersection. ...
    (microsoft.public.win32.programmer.directx.graphics)
  • Re: pick closest mesh by mouse
    ... > closesthit.distance does indeed give you the distance along that ray. ... > intersection code isn't working at all. ... >>> be used to compute the distance to the initial ray of selection. ...
    (microsoft.public.win32.programmer.directx.managed)
  • Re: Mesh.IntersectSubset
    ... It will now successfully return the distance of the ray, ... intersection code I used was relative to how my culling was done. ... screen but in this case its literally the center of the viewport which you ... height variables set up when you created your directX object and scene. ...
    (microsoft.public.win32.programmer.directx.managed)
  • Re: Reflecting a ray off a line
    ... to find an intersection between a ray and a line you just solve this ... Therefor we rearrange ... there are cases in which a line and a ray don't intersect, ... then substitute t in the first equation. ...
    (comp.graphics.rendering.raytracing)