ModelsUnderRay - show direction?

[AndrewNock]

Hey all, before i spend a bit of time on this, wanted some input, and to see if
anyone has done anything.

I have got a few objects sending out rays for collision detection, but
sometimes unsure where they are going and what direction etc. I want to make
something that small cylinders will be made in the direction and for the
distance of the ray.

Any ideas?

Andy

[duckets]

Hi Andrew,

(After typing this up in notepad, I accidentally posted it in response to your
crane question instead of this thread!)


To align a model to a vector (such as your ray cast vector), you can use
something like this:

tiltAngle = vector(0,0,1).anglebetween(theVector)
tiltVector = theVector.perpendicularto(vector(0,0,1))
theModel.transform.rotation = vector(0,0,0)
theModel.transform.rotate(rayBeam.transform.positi on,tiltVector,-tiltAngle)

To align it to a ray vector, and display it correctly, if your model was a
'box' from director's default box primitive, you would then want to position it
halfway between the ray cast source, and the ray intersect position (because
the box's origin is in its centre), and scale it so that it extends the full
distance between the two.

Luckily this is actually a frequently asked question, and something that I do
quite a lot myself - so I happen to have some demo movies showing it in action!

First here's some roughly compiled information about modelsUnderRay(), mostly
advice I've given out on various director mailing lists in the past:


[url]http://www.robotduck.com/content/articles/director/collision/modelsUnderRay/mode[/url]
lsUnderRay.txt

And here are a few demos of how it can be used effectively (including one with
visible beams as you described!)


[url]http://www.robotduck.com/content/articles/director/collision/modelsUnderRay/grou[/url]
ndCollision.htm


[url]http://www.robotduck.com/content/articles/director/collision/modelsUnderRay/grou[/url]
ndCollisionAndAlign.htm


[url]http://www.robotduck.com/content/articles/director/collision/modelsUnderRay/grou[/url]
ndCollisionAndAlignInterpolated.htm


[url]http://www.robotduck.com/content/articles/director/collision/modelsUnderRay/wall[/url]
Collision_V-Ray.htm


[url]http://www.robotduck.com/content/articles/director/collision/modelsUnderRay/wall[/url]
Collision_V-Ray_visibleBeams.htm



Enjoy!


- Ben