Re: Why Open CASCADE?

Bryan Bishop

unread,

Jan 25, 2012, 1:19:16 PM1/25/12

to shapesm...@googlegroups.com, Zhongpeng Lin, Open Manufacturing, Bryan Bishop

On Wed, Jan 25, 2012 at 11:56 AM, Zhongpeng Lin <lin...@gmail.com> wrote:

Sorry if this question is too naive, I am new to 3D modeling. It seems that WebGL+Three.js is capable of doing 3D modeling, why do we need Open CASCADE? What's the functional decomposition between WebGL and Open CASCADE? An architectural diagram of Shapesmith might be helpful.

Because WebGL does not have routines and methods for boolean operations on NURBS. WebGL is just for rendering.

- Bryan
http://heybryan.org/
1 512 203 0507

Andrew Shindyapin

unread,

Jan 25, 2012, 1:32:58 PM1/25/12

to openmanu...@googlegroups.com, shapesm...@googlegroups.com, Zhongpeng Lin, Bryan Bishop

This is changing with OpenJSCad: http://joostn.github.com/OpenJsCad/

--
You received this message because you are subscribed to the Google Groups "Open Manufacturing" group.
To post to this group, send email to openmanu...@googlegroups.com.
To unsubscribe from this group, send email to openmanufactur...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/openmanufacturing?hl=en.

Bryan Bishop

unread,

Jan 25, 2012, 1:49:52 PM1/25/12

to Andrew Shindyapin, Bryan Bishop, openmanu...@googlegroups.com, shapesm...@googlegroups.com, Zhongpeng Lin

On Wed, Jan 25, 2012 at 12:32 PM, Andrew Shindyapin <andrei.s...@gmail.com> wrote:

On Wed, Jan 25, 2012 at 1:19 PM, Bryan Bishop <kan...@gmail.com> wrote:

Because WebGL does not have routines and methods for boolean operations on NURBS. WebGL is just for rendering.

This is changing with OpenJSCad: http://joostn.github.com/OpenJsCad/

I don't see how that changes what I said. That's for boolean operations on tessellated meshes (planar). The math is very different...

Bryan Bishop

unread,

Jan 25, 2012, 3:16:51 PM1/25/12

to shapesm...@googlegroups.com, Bryan Bishop, Andrew Shindyapin, openmanu...@googlegroups.com, Zhongpeng Lin

On Wed, Jan 25, 2012 at 2:08 PM, Benjamin Nortier <bjno...@shapesmith.net> wrote:

OpenJscad is based on Constructive Solid Geometry (CSG). CSG is easier, but is a mesh-based approach, whereas BRep is an analytical approach. Similar to vector vs raster graphics in some ways.

Right.. and another complicating factor is that you can technically do CSG on top of b-reps ;-) Or at least, it's my understanding that CSG always refers to just "making a tree of some unit shape, plus some boolean operation" w/o care for what the shape format is.

Nathan McCorkle

unread,

Feb 23, 2012, 1:25:48 PM2/23/12

to openmanu...@googlegroups.com

So is openJsCad mature?

--
Nathan McCorkle
Rochester Institute of Technology
College of Science, Biotechnology/Bioinformatics

Reply all

Reply to author

Forward