Grouping with section plane weirdness with SU 5, 6 and 7
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Hi folks.
Try this:
1 - Create a cube (a rectangle pulled up will do).
2 - Add a Section plane on one face.
3 - Select the cube and the Section plane.
4 - Make a group with the selection.
You will see that the face on which you applied the Section Plane will reappear outside the group.
You will also discover that it has been removed from the cube inside the group.
If you show the Model Statistics and observe it before and after the grouping you will see that the number of edges changes.
Before grouping it is 12 and after it is 16. The number of faces stays the same at 6.
Strange ?!?!?!
Just ideas.
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Im guessing the face doesnt appear inside the group as SU treats it as hidden geometry, which makes sense to me (i.e. you wouldnt want to start grouping bits of hidden geometry, as youd never know what was being grouped in a complex model.)
As for the extra edges, SU must have to make some more edges to compensate for the fact that some of the geometry is grouped, so the cube and the face no longer share any edges so SU makes some more edges.
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Hi Remus, hi folks.
If you go inside the group, you will see that the face has dispeared. All its edges are still there but the face itself is gone. Of course, SU had to create four additional edges to support it outside the group.
You idea of not grouping hidden geometry would be good but I tried this:
1 - I created a vertical cylinder, after pulling up an horizontal circle.
2 - I added a vertical section plane and I slid it sligthly to hide about one quarter of the cylinder. I grouped the cylinder and the section plane. No additional surface was created and, when I went inside the grouop and deleted the section plane, the cylinder was intact. The Model statistics window showed no change in the number of geometries. There were 72 edges and 26 faces in my model. Itried again without sliding the Section plane and got the same result.
Just ideas.
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More guessing: SU groups the hidden geometry in the cylinder case because there is no piece of geometry that is wholly hidden i.e. SU sees it all as connected faces, whereas with the cube the hidden face is entirely separate from the grouped geometry.
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Hi folks.
A follow-up with the cylinder. I made my test with hiden geometry hidden. If hidden geometry is visible, the result is as it was with the cube. Sliding the Section plane toward the cylinder axis, will create more facets outside the group and remove them from the cylinder inside the group. This can be verified with the statistics.
Just ideas.
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