Catmull Clark Subdivide

classic Classic list List threaded Threaded
6 messages Options
Reply | Threaded
Open this post in threaded view
|

Catmull Clark Subdivide

Bo Schwarzstein-2
Hi everyone,
    I want to know what's the different about Catmull Clark subdivide surface algorithm between the CGAL and the paper from CalTech named " Rapid Evaluation of Catmull-Clark Subdivision Surfaces", anybody could help me ? Thanks.
Reply | Threaded
Open this post in threaded view
|

Re: Catmull Clark Subdivide

Peter Schröder
Bo Schwarzstein wrote:
    I want to know what's the different about Catmull Clark subdivide surface algorithm between the CGAL and the paper from CalTech named " Rapid Evaluation of Catmull-Clark Subdivision Surfaces", anybody could help me ?
The CGAL CC code takes a mesh and modifies it to a new mesh which corresponds to 1 step of CC subdivision. It does so uniformly. A certain version of the CC rules is used.

The rapid evaluation code is based on pre-evaluated (in a texture map) basis functions which are composed (using texture scale/add) at runtime using the original coarsest level control points as weights. No meshes are produced.

peter
Reply | Threaded
Open this post in threaded view
|

Re: Catmull Clark Subdivide

Bo Schwarzstein-2
Hi, thanks for your reply.
 
I foundt the MESH demo made by CGAL developers and researchers, modifyed some code so it can be compiled in VS2005.
 
I found that it can't reading the wavefront obj file I exported from Maya 2008, I checked the ascii file but found no problem. It always shows memory access error. I checked the source code, do not know whether it was caused by my mesh - triangles and quads.
 
Because the polygon mesh maybe not perfect, owns some self intersections, so I also want to know whether CGAL CC could handle it.
 
Thanks !
 

Sent: Wednesday, July 30, 2008 2:07 AM
Subject: Re: [cgal-discuss] Catmull Clark Subdivide

Bo Schwarzstein wrote:
    I want to know what's the different about Catmull Clark subdivide surface algorithm between the CGAL and the paper from CalTech named " Rapid Evaluation of Catmull-Clark Subdivision Surfaces", anybody could help me ?
The CGAL CC code takes a mesh and modifies it to a new mesh which corresponds to 1 step of CC subdivision. It does so uniformly. A certain version of the CC rules is used.

The rapid evaluation code is based on pre-evaluated (in a texture map) basis functions which are composed (using texture scale/add) at runtime using the original coarsest level control points as weights. No meshes are produced.

peter
Reply | Threaded
Open this post in threaded view
|

Re: Catmull Clark Subdivide

Sebastian Marino
Note that indexing for OBJ files begins at 1, not zero.  If you're having a memory error.

On Tue, Jul 29, 2008 at 8:04 PM, Bo Schwarzstein <[hidden email]> wrote:
Hi, thanks for your reply.
 
I foundt the MESH demo made by CGAL developers and researchers, modifyed some code so it can be compiled in VS2005.
 
I found that it can't reading the wavefront obj file I exported from Maya 2008, I checked the ascii file but found no problem. It always shows memory access error. I checked the source code, do not know whether it was caused by my mesh - triangles and quads.
 
Because the polygon mesh maybe not perfect, owns some self intersections, so I also want to know whether CGAL CC could handle it.
 
Thanks !
 

Sent: Wednesday, July 30, 2008 2:07 AM
Subject: Re: [cgal-discuss] Catmull Clark Subdivide

Bo Schwarzstein wrote:
    I want to know what's the different about Catmull Clark subdivide surface algorithm between the CGAL and the paper from CalTech named " Rapid Evaluation of Catmull-Clark Subdivision Surfaces", anybody could help me ?
The CGAL CC code takes a mesh and modifies it to a new mesh which corresponds to 1 step of CC subdivision. It does so uniformly. A certain version of the CC rules is used.

The rapid evaluation code is based on pre-evaluated (in a texture map) basis functions which are composed (using texture scale/add) at runtime using the original coarsest level control points as weights. No meshes are produced.

peter



--
Sebastian Marino
Chief Software Architect
Makani Power, Inc., Alameda, Ca.
www.makanipower.com
510.387.8077
Reply | Threaded
Open this post in threaded view
|

Re: Catmull Clark Subdivide

Bo Schwarzstein-2
I decided to write some code to manually load wavefront obj file into memory, all the polygon mesh in maya will be triangulated, test whether the error will be happened too.
 
Thanks for your reply.

Sent: Wednesday, July 30, 2008 11:17 AM
Subject: Re: [cgal-discuss] Catmull Clark Subdivide

Note that indexing for OBJ files begins at 1, not zero.  If you're having a memory error.

On Tue, Jul 29, 2008 at 8:04 PM, Bo Schwarzstein <[hidden email]> wrote:
Hi, thanks for your reply.
 
I foundt the MESH demo made by CGAL developers and researchers, modifyed some code so it can be compiled in VS2005.
 
I found that it can't reading the wavefront obj file I exported from Maya 2008, I checked the ascii file but found no problem. It always shows memory access error. I checked the source code, do not know whether it was caused by my mesh - triangles and quads.
 
Because the polygon mesh maybe not perfect, owns some self intersections, so I also want to know whether CGAL CC could handle it.
 
Thanks !
 

Sent: Wednesday, July 30, 2008 2:07 AM
Subject: Re: [cgal-discuss] Catmull Clark Subdivide

Bo Schwarzstein wrote:
    I want to know what's the different about Catmull Clark subdivide surface algorithm between the CGAL and the paper from CalTech named " Rapid Evaluation of Catmull-Clark Subdivision Surfaces", anybody could help me ?
The CGAL CC code takes a mesh and modifies it to a new mesh which corresponds to 1 step of CC subdivision. It does so uniformly. A certain version of the CC rules is used.

The rapid evaluation code is based on pre-evaluated (in a texture map) basis functions which are composed (using texture scale/add) at runtime using the original coarsest level control points as weights. No meshes are produced.

peter



--
Sebastian Marino
Chief Software Architect
Makani Power, Inc., Alameda, Ca.
www.makanipower.com
510.387.8077
Reply | Threaded
Open this post in threaded view
|

Re: Catmull Clark Subdivide with TexCoord

Bo Schwarzstein-2
In reply to this post by Sebastian Marino
Hi Sebastian, you are right, the bug is the index, I have successfully subdivide the mesh, but I do want to know how to deal with the texture cooridinates, anybody who can help me ? Thanks very much.

Sent: Wednesday, July 30, 2008 11:17 AM
Subject: Re: [cgal-discuss] Catmull Clark Subdivide

Note that indexing for OBJ files begins at 1, not zero.  If you're having a memory error.

On Tue, Jul 29, 2008 at 8:04 PM, Bo Schwarzstein <[hidden email]> wrote:
Hi, thanks for your reply.
 
I foundt the MESH demo made by CGAL developers and researchers, modifyed some code so it can be compiled in VS2005.
 
I found that it can't reading the wavefront obj file I exported from Maya 2008, I checked the ascii file but found no problem. It always shows memory access error. I checked the source code, do not know whether it was caused by my mesh - triangles and quads.
 
Because the polygon mesh maybe not perfect, owns some self intersections, so I also want to know whether CGAL CC could handle it.
 
Thanks !
 

Sent: Wednesday, July 30, 2008 2:07 AM
Subject: Re: [cgal-discuss] Catmull Clark Subdivide

Bo Schwarzstein wrote:
    I want to know what's the different about Catmull Clark subdivide surface algorithm between the CGAL and the paper from CalTech named " Rapid Evaluation of Catmull-Clark Subdivision Surfaces", anybody could help me ?
The CGAL CC code takes a mesh and modifies it to a new mesh which corresponds to 1 step of CC subdivision. It does so uniformly. A certain version of the CC rules is used.

The rapid evaluation code is based on pre-evaluated (in a texture map) basis functions which are composed (using texture scale/add) at runtime using the original coarsest level control points as weights. No meshes are produced.

peter



--
Sebastian Marino
Chief Software Architect
Makani Power, Inc., Alameda, Ca.
www.makanipower.com
510.387.8077