OCC 7.2 improvements

[DeepSOIC]

I am reading through OCC 7.2 release notes, and I want to share some things.
This post will probably grow, as I discover more.

==for users==
1. Improved 3d offset. It can now do this:

3d offset improved.png (53.69 KiB) Viewed 1753 times

I don't know, since when it became possible. You should tick "Intersection" in dialog/properties for this to work. YAY!



==for coders==
1. New object for storage of shape history, BRepTools_History. Should be a good thing for toponaming.
2. ShapeUpgrade_UnifySameDomain got some fixes. I don't know if FC still uses Tanderson's algorithm... if it still is, I think it's time to expose toe opencascade's algo to see if it's any better.
3. BOPAlgo_Tools::WiresToFaces allows creating planar faces from the planar wires. In general, the input wires are non-manifold and may be not closed, but should share the coinciding parts. The wires located in the same plane and completely included into other wires will create holes in the faces built from bigger wires.
Time to ditch FaceMakerBullseye, with its toponaming instability?
4. Gluing operation.
The Gluing mode is a new option for Boolean operations (BOPs). It should massively speed up fusions when objects just touch. It does so by omitting the slowest part of algo - searching and computing face-face intersection curves.
5. There is now an OCC replacement for Part Slice (which I hacked up from generalfuse), BOPAlgo_Splitter.
6. Refactored BOP error-and-warning reporting mechanism.
▪ Methods HasErrors() and HasWarnings() can be used to check for the presence of error and warning alerts;
▪ DumpErrors/DumpWarnings methods can be used to dump the error and warning messages as text.
▪ Method GetReport() provides access to all alerts; see class Message_Report for details.

[damian]

Orientation of the shapes in the container

The following methods allow reorienting shapes in the containers:

BOPTools_AlgoTools::OrientEdgesOnWire correctly orients edges on the wire;
BOPTools_AlgoTools::OrientFacesOnShell correctly orients faces on the shell.

https://www.opencascade.com/doc/occt-7. ... po_tools_3

[tanderson69]

2. ShapeUpgrade_UnifySameDomain got some fixes. I don't know if FC still uses Tanderson's algorithm... if it still is, I think it's time to expose toe opencascade's algo to see if it's any better.

SUUSD = ShapeUpgrade_UnifySameDomain

As far as I know it still does. The last time I checked SUUSD, there were still about 5 test cases that didn't pass where model refine did. That was for occt 6.9.1. The tests and a log file are located in */data/tests/ModelRefineTests. You could use those tests in DRAWEXE and see where SUUSD stands. I am thinking SUUSD is good enough. I know there are some cases where SUUSD works better. I just came across one the other night. https://forum.freecadweb.org/viewtopic. ... 10#p227755 model refine won't join across different surface types, but SUUSD will and worked for that file.

[NormandC]

I just came across one the other night. https://forum.freecadweb.org/viewtopic. ... 10#p227755 model refine won't join across different surface types, but SUUSD will and worked for that file.

Interesting.

==for users==

Hidden line removal algorithms (HLR) got a lot of improvements that are very useful to TechDraw. Projected views are a lot more reliable.

There's also cool stuff in TechDraw not possible with lesser OCCT versions, not sure it's thanks to what OCCT stuff exactly:

FC017_TechDraw_Perspective_View_01.png (12.66 KiB) Viewed 1691 times

Oops, missing edge!