Jump to content
  • 1
barkest

Convert to subdivision not work correctly

Question

On the attachment I took a simple extrude and converted it to a sub div object. I then used crease all to put it back to the original shape. As you can see it did not work. The original object can be seen.

 

Not sure what to do if it fails on such a simple object?

 

thanks

sub div not working.jpg

Share this post


Link to post

17 answers to this question

Recommended Posts

  • 0

Nope, same thing happened here in a test, the same odd fins appear even though they have no cage geometry defining them.

 

58b08e36385f2_ScreenShot2017-02-24at2_48_59PM.png.00f62713494048be7a84e945357b0e87.png

 

Submitting this as a bug now. VB-139591

Share this post


Link to post
  • 0

If I take a polygon and convert it to a sub div then extrude the polygon face is there a way to close the hole on the bottom on the sub div object (assume I extrude upwards)

 

 

sub div from polygon.jpg

Share this post


Link to post
  • 0

I don't think so - have you tried extruding first and converting to Subdivision next.

Is there a way to loose the webbing. If not I wish for one. It makes Subdivision unusable for many re-entrant objects.

 

Screen Shot 2017-02-24 at 2.14.06 PM.png

Edited by bcd
  • Like 1

Share this post


Link to post
  • 0

sorry - just hijacked your other thread to highlight this issue. I went with a fillet instead of Subdivision because of exactly this issue.

Share this post


Link to post
  • 0

thanks I was just looking for other methods to get around the other now known bug

 

After my all day pod issues I decided to get into Sub Div modelling but have not had a great start :(

 

I am sure things will start looking up

Share this post


Link to post
  • 0

@barkestHi, Morning. Use the bridge mode to close off the base, then use the crease mode to make them square again. As for the surface at the top not sure yet.

Capture.JPG

Share this post


Link to post
  • 0

Hi, Is there a way around this? See attached when you convert a shape like this you get crossover of the mesh which stays as a surface, even is you try to crease it out. Is there a way????

Capture.JPG

Share this post


Link to post
  • 0

@barkestSo getting rid of the overlapping shape is easy,  Hit face hole mode and select top, its then gone. But trying to bridge again is causing an issue.

Share this post


Link to post
  • 0

So if you really want to do it with starting with a polygon, use the hole to delete the offending top and use subdivision mirror and you have a complete object. if you dont want to keep it as mirror hit mirror again and it becomes one object .HTH

Capture.JPG

  • Like 1

Share this post


Link to post
  • 0

This is Senthil Prabu...

 

Thanks Alan for the nice video,

Following tips may help to understand the tool better...

 

Reason for the Crossover mesh:

     The particular cage face is a non-quad cage face, so the OpenSubdiv Library use to generate subdivision mesh like this only.  At present the workaround is to convert that face into multiple faces.

 

From the Alan's video:

-> "Face hole" is used to toggle on/off its dependent subdivision mesh.  In the video, instead of using "Face hole", Use Transform mode, select the face and hit "Delete" button, the particular cage face will be

      deleted.  Then you can use the Bridge mode to close the face with multiple faces as you did for bottom face.

-> To Crease everything:

         Being inside the "Edit Subdivision" tool with a Subdivision object is selected.  User can right click to get the following context menus to crease/uncrease everything.

  • Crease All Edges
  • Smooth All Edges
  • Crease All Vertices
  • Smooth All Vertices.

 

 

 

Share this post


Link to post
  • 0

This thread was very helpful for finding a workaround. Is the self intersection created considered a bug? It doesn't take much to get it to happen.

 

Kevin

58d2a205362a2_ScreenShot2017-03-22at9_10_18AM.png.3efddcadfa2e64a19578beb843e2c4cc.png

Share this post


Link to post
  • 0

As explained before, for non-convex polygon, the opensubdiv library generates mesh like this only.

 

Workaround:

->Delete the face with Transform mode (select the face and press delete key),

-> Use Bridge mode to create two faces as shown below.

-> repeat the same procedure for other side of the face too.

 

Workaround.png.b6d17fa4ee91ef3ad83076e2f69c988f.png 

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

 

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.

×