Go Back   AC3D Forums > General > AC3D General
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 18th April 2008, 03:13 PM   #1
bitboy0
Junior Member
Junior member
 
Join Date: Apr 2008
Posts: 5
Default some Problems with boolean...

Hi Folks.

I do PovRay a while now... not very hard things, but I know about the primitives and how to add or substract primitives to get the form I need.

AC3D looks good and helps modelling... fine thing! But If I do some simple things it doesn't work the usual way... f.e.:

first I make a cylinder (x,y,z) = 2,2,2 at the center of the workspace (0,0,0) where the ends of the cylinder are at "y"
Then I make a second one, the same drection but 1,3,1 ... so it is longer than the first one but smaller.

Then I substract the secon one from the first one... I expect to see a hole in the middle of the bigger cylinder -> a pipe.

What I get is "almost" a pipe, but the edges somtimes are looking bad. some of the vertexes are not where they should be.. This is not nice! What is wrong there?

(see Picture)

regards
Attached Images
 
bitboy0 is offline   Reply With Quote
Old 18th April 2008, 06:15 PM   #2
Klyde
Senior Member
Professional user
 
Klyde's Avatar
 
Join Date: Mar 2008
Location: USA
Posts: 227
Default Re: some Problems with boolean...

Don't really know, but why not just create a ellipse and then extrude it along the y axis for a pipe?
__________________
VR is the future, The future is NOW!!.
Klyde is offline   Reply With Quote
Old 18th April 2008, 07:36 PM   #3
bitboy0
Junior Member
Junior member
 
Join Date: Apr 2008
Posts: 5
Default Re: some Problems with boolean...

Uhm... because it is one of the basic features? I know there are more expensive programs out there ... but even the povray program can do this really easy job without problems!

There are some more Problems with "dividing" surfaces ... there are iregular vertexes too ... Sometimes there are holes in a surface after doing that .. or a kind of "needles" ...

If I place an object behind a transparent "window" sometimes it is invisible behind that ... after grouping and ungrouping it is ok ...

I guess there is a workaround for the most Problems ... it would be better to fix that little bugs, isn't it?
bitboy0 is offline   Reply With Quote
Old 18th April 2008, 07:43 PM   #4
MrSteve
Senior Member
Professional user
 
MrSteve's Avatar
 
Join Date: Feb 2008
Location: Brighton, England
Posts: 231
Default Re: some Problems with boolean...

I know what your problem is, if the verticed meet on the exact same line then it struggles with creating new geometry for the new object see below

Name:  subtra1.JPG
Views: 317
Size:  17.7 KB
however if you rotate it just slightly like below


Name:  subtra2.JPG
Views: 315
Size:  18.2 KB
you should start to see an improvment


Name:  subtra3.JPG
Views: 314
Size:  9.6 KB
Let me know how this works for you!

Steve
__________________
MarshallARTS, Playtime for the professionals!

http://www.turbosquid.com/Search/Ind...lAuthorExact/y
MrSteve is offline   Reply With Quote
Old 19th April 2008, 05:09 PM   #5
bitboy0
Junior Member
Junior member
 
Join Date: Apr 2008
Posts: 5
Default Re: some Problems with boolean...

thanks alot! Yes it is a real workaround! Nevertheless I hope they will fix this bug!.

regards
bitboy0 is offline   Reply With Quote
Old 19th April 2008, 06:11 PM   #6
MrSteve
Senior Member
Professional user
 
MrSteve's Avatar
 
Join Date: Feb 2008
Location: Brighton, England
Posts: 231
Default Re: some Problems with boolean...

no problem!
__________________
MarshallARTS, Playtime for the professionals!

http://www.turbosquid.com/Search/Ind...lAuthorExact/y
MrSteve is offline   Reply With Quote
Old 19th April 2008, 10:56 PM   #7
foxa
Senior Member
Professional user
 
Join Date: Jun 2003
Location: Greensboro NC, USA
Posts: 337
Default Re: some Problems with boolean...

A couple of quick notes.
1) Even the "expensive" programs have problems with booleans, and if you are going to sub divide your model fuggeddaboudit. Booleans do not work for proper edge flow and quad surfaces.

2) If you are going to use booleans in AC3D scale you model up to a larger size, use the boolean and then scale it back down (I learned that one from Andy).

Have Fun

Art
foxa is offline   Reply With Quote
Old 21st April 2008, 04:17 AM   #8
bitboy0
Junior Member
Junior member
 
Join Date: Apr 2008
Posts: 5
Default Re: some Problems with boolean...

Quote:
Originally Posted by foxa View Post
...If you are going to use booleans in AC3D scale you model up to a larger size, use the boolean and then scale it back down (I learned that one from Andy).
Thx too! That helps... btw. what is the biggest size I can use for objekts? Is there a border?
Quote:
Originally Posted by foxa View Post
Have Fun
Art
I'll have Fun! I promise

regards
bitboy0 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -4. The time now is 04:23 PM.


AC3D Forum
(C) Inivis Limited 2020