Model.raytest and Entity visibillity

Al Hart

Thanks tons, ThomThom, by tool is working again!

thomthom

@al hart said:

@thomthom said:

@al hart said:

It's what I do in my wrapper method that ensures the ray doesn't stop on hidden entities.

[EDIT: I see some code in a previous post. I will try it out]

Thanks,

Is there some code here in this thread already, or can you show me what you are doing to skip hidden geometry?

Bottom of first post:
http://forums.sketchucation.com/viewtopic.php?f=180&t=28059#p243311

Chris Fullmer

I've used a little recursive method to check what I am hitting. If I do not like what I hit, I recall the method supply the Point3d of the last thing I hit. It remakes the ray and casts it again until I hit what I'm after.

It has worked perfectly so far. But I'm concerned about the rays that don't work if they are shot through the groundplane? Is that still an issue in 8?

thomthom

@chris fullmer said:

It has worked perfectly so far. But I'm concerned about the rays that don't work if they are shot through the groundplane? Is that still an issue in 8?

"Still an issue in 8"? Has it been an issue before?
At it turned out - it's not only when the ray passes through the axis planes - but also at random times. model.raytest is fubar in SU8 - not reliable.

kwalkerman

Ok, so here's an issue with the new way raytest works (ie it sees all entities, visible and hidden).

There are times when a ray will hit multiple entities at the same point. In SU 7, model.raytest will return only one of those entities. It's easy to find all entities by hiding any entities that are hidden, but under the new version of SU, only one of the entities will be found. Another thing, which is interesting, is that if there are multiple entities in the same location, SU will return the same entity first, regardless of the direction of the ray.

Try this code:


model = Sketchup.active_model
p1 = Geom;;Point3d.new(0,0,0)
p2 = Geom;;Point3d.new(20,20,0)
p3 = Geom;;Point3d.new(0,20,0)
f = model.entities.add_face(p1,p2,p3)
model.entities.add_group([f])
model.entities.add_face(p1,p2,p3)
p4 = Geom;;Point3d.new(5,10,-5)
p5 = Geom;;Point3d.new(5,10,5)
ray1 = [p4, Geom;;Vector3d.new(0,0,1)]
item1 = model.raytest ray1
ray2 = [p5, Geom;;Vector3d.new(0,0,-1)]
item2 = model.raytest ray2
item1 == item2

#==> returns TRUE!

I can't currently think of a ruby workaround for this. The new version of raytest will limit the ability to get all objects at a certain location.

As I suggested before, I think it makes the most sense to extend the native raytest so that you can specify whether or not you want the ray to be allowed to show hidden objects.

--
Karen

Al Hart

@kwalkerman said:

I can't currently think of a ruby workaround for this. The new version of raytest will limit the ability to get all objects at a certain location.

--
Karen

It would be fairly painful, but you could start an undo operation, delete each item as it is found (rather than changing the starting point of the ray, ot just hiding the object) and continue until all objects are found (saving their object IDs), then abort the operation to restore everything to the database.

tomasz

@kwalkerman said:

As I suggested before, I think it makes the most sense to extend the native raytest so that you can specify whether or not you want the ray to be allowed to show hidden objects.

I have proposed it TWO years ago.... G Team isn't responsive.

Chris Fullmer

Hmm, nevermind. I retract this post, I was confused

thomthom

Right, so the raytest should have an argument to ignore hidden.

Al Hart

@thomthom said:

Right, so the raytest should have an argument to ignore hidden.

And, hopefully, they will make it an optional argument, so they don't break all the existing ruby files once again.