Hi,
> Looking ahead a little bit (while I'm thinking about work already
> done) - once you are happy with the curves being produced by the
> intersection routine, the next step will be to "pull back" the 3D
> curve into the UV parameter spaces of the intersecting surfaces in
> order to create 2D trimming curves (and hence new trimmed surfaces
> that will be used to form the evaluated breps). There is logic for
> that task in the step-g converter - it needs to be moved into librt,
> but that will probably be a lot less work than re-creating it. Again,
> that's down the road after the intersection issue itself has been
> worked out, but I thought I'd mention it.
The 2D curves in UV parameter spaces can be created within the intersection
process, and I have finished it now. It works quite well at present, although
it might still need some improvement.
So I wonder how to deal with these 2D trimming curves. How to use them to
generate new trimmed b-rep surfaces? That is, if we want to form the evaluated
b-reps, we need to know the topological structure of the whole solid. For
example, we evaluate a union of two intersecting spheres, we need to know which
side of the intersecting curve is inside the union, and which side is the outer
boundary of the union. Could you please describe this in more detail?
As for the threshold of bounding boxes' sizes, I think using
INTERSECT_MAX_DEPTH is just OK. If we use a constant value to decide whether a
bounding box is small enough, it's not quite suitable because the original
sizes of the surfaces can vary significantly. So using a max depth we guarantee
that we arrive at a constant proportion of the original size in UV parameter
spaces (because after each split the UV domains both become half). What's your
opinion?
Cheers!
Wu
------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions
will include endpoint security, mobile security and the latest in malware
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
BRL-CAD Developer mailing list
brlcad-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/brlcad-devel
