Jump to content
  • 1
markdd

Clipcube- Is this strange behaviour?

Question

In the picture below some extrudes render as solid objects and are filled red at the boundary of the ClipCube and some are open. I am confused as to what makes one extrude "Solid" and another hollow. (All the extrudes are made from closed polygons.) The only difference between them that I can find is that the "hollow" extrudes are part of a solid addition.5979dc4c28d7e_ScreenShot2017-07-27at13_25_17.png.9381cf767244b91cffd3bd17483e3069.png

When I ungroup the Solid addition I get what I would expect.

5979dd5c672a7_ScreenShot2017-07-27at13_32_18.png.08a0c7e7a48c1200491953f5e306fb4b.png

 

 

Share this post


Link to post

17 answers to this question

Recommended Posts

  • 0

I would file it as a bug. There is a problem with some solids operations creating geometry with flipped normals. I suspect that's what is causing what you're seeing. I used to see it all the time when preparing objects for 3d printing but its improved in newer versions.

 

Kevin

 

Share this post


Link to post
  • 0

It is the standard problem with Extrudes.

The base 2D polygon had to be flipped (or reversed direction) while being extruded.

That is why not all face normals point outwards as they should.

 

I am just wondering why that problem persists embeded in a Solid Addition/Subtraction.

That makes kind of Solids from Extrudes. And for me that healed previous Extrudes

when Exporting to other 3D Apps so far.

 

And normally I was used to have no red clip faces at all for any Extrudes or its derivates

contained in PIOs.

Edited by zoomer

Share this post


Link to post
  • 0

Bug for sure. Users should be able to expect that ANY solid, regardless of what type of solid, will be properly filled by both clip cubes and sections when cut.

  • Like 2

Share this post


Link to post
  • 0

intersecting Geometry?

 

Make two identical cubes, and have them "crash into" each other and then use the clip cube.. you should see similar behaviour.

When you do a solid addition to these cubes that behaviour will revert to normal.

 

On the extrudes source poly, make sure you don't have two identical polys over each other. that'll produce the same behaviour

Share this post


Link to post
  • 0

@RussUWhat I found in a clean file with two intersecting cubes was that the intersection was hollow, the rest solid. As you suggest, doing a solid addition made both solid. That is NOT what happened in the earlier drawing when undoing the solid addition made the extrudes solid when before they were hollow!

Screen Shot 2017-07-27 at 16.58.38.png

Share this post


Link to post
  • 0

Ok... Now go into the source geometry of a cube, copy the rectangle, paste it, and then move it directly on top of the original so you have two identicals... then view the result in the clip cube

Share this post


Link to post
  • 0

This happens!

597a0fbf06597_ScreenShot2017-07-27at17_02_56.png.3ff9af22682a98620f590cf9001c72fe.png

I have checked the original geometry in the drawing that started this and there is nothing untoward that I can find. In this instance making the extrudes a solid addition causes them to be hollow! 

Share this post


Link to post
  • 0

So the clip cube has no problems with Extrudes problems itself as I mentioned at all,

but with overlapping Volumes.

That is fine.

 

So does that also happen when Objects just Touch ?

(no current VW availabe here atm)

The problem I see with clip cube section faces for multi component slabs ?

Share this post


Link to post
  • 0

Hi Zoomer

 

The problem objects are simple extrudes when made into solid additions.

 

Mark

Share this post


Link to post
  • 0
15 minutes ago, markdd said:

simple extrudes

Can you post a file?

 

Doesn't need to be the whole thing, just copy/paste the problem stuff into a new file.

Just another thought though, OpenGL can have issues when your model is a million miles away from the file origin. Can you put a 3d locus at 0,0,0 to see how far away your stuff is?

Share this post


Link to post
  • 0

As far as I understood by your examples, it may not be related to Extrudes at all,

maybe just when 2 Volumes overlap that clip cube can't create the red section face ?

As your normal Extrudes look fine when not overlapping other geometry.

 

And just in your special file, where the typical self healing effect of Add/Sub Solid containers

doesn't effect as usual.

Share this post


Link to post
  • 0

Here is the file with the offending objects!

 

The 0,0,0 Point is very close by. The geometry is slightly wobbly as the file originated as a dwg probably made using some sort of point cloud device. I'm wondering if that is the source of the problem.... Take a look and see what you think.

Clip Cube.vwx

Share this post


Link to post
  • 0

You have discovered a bug.

I did this to reproduce.

Made a 50x50x50 cube. Duplicated it twice, to make three.

Then corner snapped the cubes to one another to make a staircase thingy... Added solids and then the clip cube presents the same weirdness.

 

I only got to it when I properly overlaid your geometry rather than snapping perfectly on edges. seems co-incident edges can confuse the cube. Can anyone else confirm?

Share this post


Link to post
  • 0
1 hour ago, markdd said:

Here is the file with the offending objects!

 

The 0,0,0 Point is very close by. The geometry is slightly wobbly as the file originated as a dwg probably made using some sort of point cloud device. I'm wondering if that is the source of the problem.... Take a look and see what you think.

Clip Cube.vwx

 

In this case its a geometry problem. VW doesn't do well when a single edge of two extrudes is joined. Its this point here -

 

597a3456c0a41_ScreenShot2017-07-27at11_41_02AM.png.c13b26db231674333b7122bd71989949.png

If I extend the height of the extruded stair down slightly like the others its fixes the issue.

 

597a3457e2870_ScreenShot2017-07-27at11_42_10AM.png.7ff2436ad3fa9f07f7968036993ad845.png

 

Kevin

Share this post


Link to post
  • 0
3 hours ago, RussU said:

Make two identical cubes, and have them "crash into" each other and then use the clip cube.. you should see similar behaviour.

Eureka - the beginnings of Clash Detection

Edited by bcd
  • Like 2

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Answer this question...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


 

7150 Riverwood Drive, Columbia, Maryland 21046, USA   |   Contact Us:   410-290-5114

 

© 2018 Vectorworks, Inc. All Rights Reserved. Vectorworks, Inc. is part of the Nemetschek Group.

×
×
  • Create New...