Some new developments on Subd Surfaces to consider; Open Subdiv

[L'Ancien Regime]

Andrew...puhleeeze..

http://area.autodesk...mudbox-and-maya

[AbnRanger]

+100

[pixo]

+1000000000

[L'Ancien Regime]

When Renderman came out with PTEX, Andrew beat everyone to the draw in instituting it in 3d Coat within a month. Can he, will he do it again???

[digman]

+1 and +2 so on and so on...

[PalSan]

+1

[pixo]

http://3d-coat.com/mantis/view.php?id=637

[AbnRanger]

http://3d-coat.com/m...view.php?id=637

Got my vote, there.

[L'Ancien Regime]

http://3d-coat.com/m...view.php?id=637

good man

[L'Ancien Regime]

This is a presentation to Autodesk employees and plugin developers at the

Autodesk University Developer conference is Las Vegas, November 26th, 2012.

Jump to 9:10 and 22:50 for demos

[L'Ancien Regime]

http://www.fxguide.c...the-good-stuff/

OpenSubdiv is a set of open source libraries that implement high performance subdivision surface (subdiv) evaluation on massively parallel CPU and GPU architectures. The code is optimized for drawing deforming subdivs with static topology at interactive framerates. The resulting limit surface matches Pixar’s RenderMan to “numerical precision”.

OpenSubdiv is free to use for commercial or non-commercial use. This is the same code that Pixar uses internally for animated film production. The posting comments that “our intent is to encourage high performance accurate subdiv drawing by giving away the “good stuff”.

"To date there are no GPU algorithms for the real-time rendering

of Catmull-Clark surfaces possessing semi-sharp creases or hierarchical

detail. In this paper, we present the first such algorithm. It

uses a combination of GPU compute kernels and hardware tessellation

to adaptively patch Catmull-Clark surfaces. Moreover, the algorithm

is exact rather than approximating (by exact we mean that

the vertices of our patch tessellations lie exactly on the limit surface

up to machine precision), and we present a variant that is capable of

creating watertight tessellations. This variant additionally satisfies

a much stronger condition: namely, that abutting patches meet with

bitwise identical positions and normals. With this stronger property

surfaces with normal displacements are also guaranteed to be

crack-free"

http://graphics.pixa...lease_info.html

Release 2.0

Pixar is targeting SIGGRAPH LA 2013 for release 2.0 of OpenSubdiv. The major feature here will be the Evaluation (eval) api. This adds functionality to:

• Evaluate the subdiv surface at an arbitrary parametric coordinate and return limit point/derivative/shading data.
  
• Project points onto the subdiv limit and return parametric coordinates.
  
• Intersect rays with subdiv limits.
  

We also expect further performance optimization in the GPU drawing code as the adaptive pathway matures.

[Carlosan]

can live clay code works fine with a surface make with ngons all time ?

i dont know

[L'Ancien Regime]

http://us.gep.autodesk-services.com/registration/5145

Description

Join special guests, Bill Polson, Dirk Van Gelder, Manuel Kraemer, Takahito Tejima, David G. Yu and Dale Ruffolo, from Pixar Animation Studios’ GPU team, as they show how real time display of subdivision surfaces helps artists be more productive, and how this code is open source and engineered for ease of integration.

OpenSubdiv is a set of open source libraries that implement high-performance subdivision surface (subdiv) evaluation on massively parallel CPU and GPU architectures. The code embodies decades of research and experience by Pixar.

Join us for this informative webinar and see how Autodesk and Pixar are working together to build technology with stunning real-time results.

[L'Ancien Regime]

Wed. April 24 Webinar with Autodesk and Pixar

You know 3d coat's only hope to compete is to implement radical advances. That's what attracts people to it; voxels, Ptex, autopo...each of these were radical revolutionary leaps by a relative unknown that brought 3d coat a lot of attention. For a time it's meant that 3d coat was actually in advance of Zbrush and Mudbox. But that window won't last for ever. This is exactly the kind of thing it needs particularly as Ptex and OpenSudiv go hand in hand.

That's sure what brought me to 3d coat: seeing Andrew implement Ptex in 3 week was an amazing stunt. I wonder if he could repeat it with Open subd and throw in some modeling tools like the tweak room extrude to use with it?

Oh and Open Subdiv implementation means Open CL implementation with it, just in time for all the people with AMD cards that want to benefit from 3d Coat.

[L'Ancien Regime]

http://w8isms.blogsp...ance-tests.html

http://gpuscience.co...ision-surfaces/

http://research.micr...oop/tog2012.pdf

Fast SDS

The question I have for Andrew though is; Is Live Clay already the equivalent of Pixar subiv surfaces?Is it even based on it?

But what this shows is that CUDA needs to be updated and improved in 3d Coat and maybe even Open CL added too.

[L'Ancien Regime]

Nvidia lectures at Siggraph 2013

 

http://www.ustream.tv/recorded/36315331

[L'Ancien Regime]

http://www.youtube.com/watch?v=Umeyd5qoykU

[L'Ancien Regime]

http://www.youtube.com/watch?v=9lFwFoCxysI

 

"This is coming as soon as we can get it done".

Edited August 22, 2013 by L'Ancien Regime

[L'Ancien Regime]

http://www.fxguide.com/featured/pixars-opensubdiv-v2-a-detailed-look/

 

Even Houdini is adopting Open SubD

 

 

 

But it's GPU dependent

 

In the GPU currently there is partial refinement of the subdivision surface. The GPU has Feature Adaptive Refinement, it refines the area of the mesh around an adaptive refinement area more densely. Subdivision is a process that does not care about topology at all.

Subdivision gives the same result as Bspline patches wherever the surface is regular,  all quads in a grid. But whereas Bsplines fail in irregular areas, subdivision always works. That was the original motivation for its invention. The OpenSubdiv GPU codepath uses this fact to aggressively render Bspline patches wherever it finds regular grids. But where the surface is irregular, OpenSubdiv continues subdividing and refining, finding more Bsplines, and so on. Both approaches give the same limit surface, except the Bspline code path is much much faster on the GPU. Typical models have regular grids on 90% or more of the surface, so this provides a huge speedup.

In the GPU codepath, the amount of subdivision and the density of Bspline tessellation are both independently controllable over the surface. So a part of the model close to camera can have more detail than a part of the same model far away.

Unfortunately, for now, the CPU codepath supports only uniform subdivision – i.e. the entire model undergoes the same amount of subdivision even if part is close to camera and part is far away. Without the flexibility offered by modern GPU tessellation, the OpenSubdiv CPU codepath is less performant than some current popular implementations, such as found in Arnold. Bill Polson agrees that the CPU code could benefit from the same level of optimization that the GPU code has had, and says the Pixar OpenSubdiv team hopes to address this in 2014.

Edited September 19, 2013 by L'Ancien Regime