[Plugin] Hatchfaces (v1.8 beta) UPDATED 15-Dec-2012

jolran

Things are not going so well. Doing a pattern like on the picture will be difficult.
Unless black and white. That's no problem to do.

TIG recommended to clone current selection to avoid bugsplats. I'm fine with that as long as doing faces only.

But that won't give much flexibility if doing a pattern like on the picture.
How to clone the edges from an array? And what if you have an edgeloop where you DON'T want a face?
And materials are still a big problems. If it where only 1 material, things would be relatively easy.
I guess faces can have attributes like materials, but how to store them and transfer to the face_clone is the question.

I'm thinking doing an intersection with face, then recreate the facecolor pattern and erase vertices outside the face.
ATM I get splats when using lot of patterns or nested components with intersection. Things are a lot more stable, since
being able to explode all the components and add entities to group AFTER the group was created.
Using few components with plenty geometry is OK. Many components are bad. Even if they contain few entities..

Could need a push with the materials.. Otherwise I probably will have to restrict the plugin features.

TIG

I'm still not entirely sure what you are are trying to do
If you want add colored shapes onto a face as a hatch pattern try this...
Make the cloned face inside the group.
Add the instances to the group.entities, placed where you will.
Apply materials to these instances.
Explode the instances and the default materials in them become their face materials and they merge with the background face.
Now you need to erase the bits outside of the face bounds.
Test all of the edges in the group.
Test their start.position and end.position, on the original face with classify_point to see if that point is 'on the face' [you need also to cover on edge, on vertex and not in hole etc] if both point test OK it's inside the original face. If one or both of them are not the you want to erase them - push into an edges2go array. The erase all of those edges and the faces go with them. Finally erase any faces with 'nil' material [in the gaps from the cloned face], and then any unfaced edges if you don't want a perimeter. You should now be left with the colored shapes trimmed to the original face's edges.

jolran

Thank's TIG, I will try.

jolran

Actually when I reread you post TIG. It is probably the way to go.

I had the idea to make a huge face. Same size as entities.bounds. Add the edgeloops from original selected face.
And then delete the original face. (Sort of oposite of the face). Then do an intersection with the components.
The result of intersection could be deleted, and all what's desired would then remain..
It is all theoretical..

jolran

I will test TIG' solution tomorrow, if time gives. I have another test to do.

If someone please tell me how I can get the pt's from a boundingbox object. It will only be 4 pt's, boundingbox from 2d hatches.. Will create a face from those points later. Had a look at Thomthoms edges from boundingbox, but it's for a whole "cube" boundingbox. Don't need that much information his script gives.

I've tried something like this. But it doesent work.

	centbox=gp2.bounds  #boundingbox object
			 centpoints=[]; range=(0..7); centbox.corner.range.each{|e| 
			  if e.valid? and e.class==Geom;;Point3d
			 
			      centpoints << e
			   end
			 }

Edited. It probably should be centbox.corner.range. I changed the original. Still doesent work..

TIG

You don't want the limits of a bounding-box - it's a rectangle, the face might be a circle ! Use my selected_face.classify_points(pt) tests for all edges after the explode/intersect etc...

jolran

Really? Bounds=boundingbox, no?

So boundingbox will not be like on the picture? darn... Typical.

TIG

entity.bounds== a bounding-box rectangular cube - even if the object is the shape of a banana

Use selected_face.classify_point() tests

jolran

Yes. That's what I want

It's for the exterior bounds of ALL entities, not the face. Then from that huge face do a boolean with the selected face.
If you intersect with the result from that you have everything intersected in a group wich can be deleted?
But ok, I will try what you say.

BTW. An exploded comp. don't always transfer the materials to the face lying underneath? It's risky.

jolran

No. Exploded instances do not merge materials to the face lying underneath. Is it supposed to happend?

TIG

On an explode it should [untested].
Alternative 'intersect' after the explode ??

jolran

Well lately I have done quite a few intersects. And the results vary. But no. Materials get lost=white default material.
However I will try intersection after exploding things.

Thanks.

Edited. Not very good results. Things are very negative at the moment. Exploding geometry connected to a face has very destructive behavior. On top of that materials don't get transfered properly, and that was the whole idea of this process.

There is more problems. Let's say I can recreate the face-clone first. No problem!
On top of the face-clone, recreate the whole component instance. Faces, edges without faces, and materials, in code.
Problem here is that I would probably have to do an intersect_with the face_clone, so the edges get connected and form new vertices at the edge crossings. And there the face materials would get lost...In the intersect_with method.

There is an theoretical alternative! I woulden't mind the opinions from TIG on this one:
If doing an component intersect_with face.edgeloops without face? That would at least give new vertices so the unwanted edges theoretical could be removed. Without affecting materials and destructive behavior (tested). But like the method TIG recommended, selected_face.classify_point(). One would need a face to compare against.
Could the face be in a different group? And deleted after comparison? What say you Massa TIG?

jolran

Yes. Something positive!

An intersect between component(hatch-pattern) and face-clone's edge loops(no face). Gives you new vertices. Without affecting materials and destroying faces! so now it's possible to erase all edges and vertices outside the face.

Will see if it's possible to make a comparison against a face in a group. Can't explode it! Destroys everything.

TIG

You can test if a point on a preselected-face in another entities context - BUT you might need to transform! the point by its container[s] transformation back to align with the preselected-face ?

jolran

Ah, sounds great, thanks. I will will try that now. Been busy with some other stuff..

jolran

I think I have a collection of points outside the face now. Plenty of iteration...
There is no way to see the real result until it starts deleting edges. Anyway, see some collection when
using puts.array of points to go

Simple question how do I convert those pt to vertices? Is there a simple way or another comparison?
I guess if getting the collection of vertices it's just a matter of deleting edges connected to that vertice. Edge.used_by?(collection of vertices) ?

jolran

Hang on! Edge.end and edge.start is vertex objects. I can't use them as point when using face.classify_point()???
In the API face.classify_points needs points as arguments.

How come I get a result from array.length? Strange... Or is there some equallity between points and vertices I'm not aware of?

Edited apparently I get some edge deleted. Almost there I think! Only did comparison against face. Maybe need against
other entities as well.

jolran

YEEEEEESSSSSSSS!!! ATM I am VERY happY!!

I'm sure there are things tome come that will put me off. BUT at least it's going forward!

I made the misstake of putting the collection of edges BEFORE the intersection. Had some problems with classify points to
edge removals. Anyway look at the picture! It has curves and circles to, with materials.
Now. Must convert it to component, so faces will cut underlying face and materials will get cleaner.
That's for tomorrow!

jolran

More tests. Overlapping components get intersected well. It's quite computable.. So one have to be careful not to overdo it I think.. We will see...This is all in 1 go. But I suppose one can split the computation up in several goes.
When I come and think of it. This is a 2D boolean!!

more tests.jpg

TIG

Do you now need to erase the uncolored faces or is that done ?

To avoid the 'z-fighting' with the existing face you could move the new group say 1mm in the originally_selected_face.normal so it's avoided...

You have indeed made a 2d-boolean tools... well done