Tools/Free/oeRay
From Osipa Entertainment
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Contents |
oeRay.rar
WHAT
This is a very basic wrapper for the closestIntersection function of MFnMesh in Python form so you can load it as a plugin node and use that node as you please. MFnMesh.closestIntersection shoots a ray from a source position, along a vector, and tells you if you hit the mesh you gave it to test against. There is a maxParam which is the maximum radius from the ray source to check against. The commenting is for someone like me, right now, Apr1, 2008 (good with MEL, but VERY new to python and Maya's API). If you're like that, you might be able to pick up some information about python and plugins in a manner that might not otherwise be an obvious way for folks who already know all this stuff to try and teach it. I tell you - us MEL guys need to be the target audience with this python stuff.
USAGE
To create the node :
createNode oeRay
Set the node a ray source position, ray direction, a collider (intersection mesh), and maxParam (maximum intersect search radius), and a choice for if you want the failure-state (no collision found / "return to source") "out position" value to be at it's farthest reach (maxParam along vector), or back where it originated (ray source). Returns if there is any collision at all, the intersect point, (or farthest reach along that direction) closest face to the intersection, and closest vertex to the intersection.
AETemplate
AEoeRayTemplate.mel should be packed along with the .py. It is an attribute editor template to arrange and organize the attributes for this node a little better. The plugin will work the same without this, but "looks" better with it.
NOTES
outFace and outVertex each return a valid index ONLY in case of a successful intersection. If there was no intersection found, they return a value of -1. This is because if we "try" to return a result otherwise, it comes back with nonsense, and isn't usable. This allows a script to use a simple filter:
if (hitFace/hitVert >= 0){ ... }
to control the potential script flow quite well. You could also check against "gotHit". outVertex is not a part of nMesh.closestIntersection's standard output, but closest face is. For this reason, we don't even bother to compute the nearest vertex unless we have intersected and have a good face to start from. Currently this cries a lot if you have "echo all commands" on in the script editor until you actually plug a mesh into it. There is some slight updating weirdness when "return to source = yes". Not sure why. It seems that it needs to fail twice to actually return if it had just succeeded..
