[Bf-committers] Weekly developer meeting, July 14, 2013

[Ton Roosendaal]

Hi,

Bart asked me for a user-readable text about OpenSubdiv for BlenderNation:

OpenSubdiv is Pixar's open source project to handle Subdivision Surface generation and drawing. In Blender this is currently handled by 1 thread only, and it needs to generate the subsurfed data first, before it can draw. 

OpenSubdiv instead:
- allows full threading, including use of GPU
- creates and draws subsurfed "on the fly", so you don't need to generate/store data
- has excellent crease support
- has adaptive (screen space) subdivision
- supports Ptex natively (non UV texture mapping)

In Cycles OpenSubdiv will replace the incomplete subdivision surface implementation, to enable faster BVH builds and lower memory usage for subdivision surfaces, as well as Ptex rendering support. 

Integrating will require a lot of work inside Blender however, so it will take some time before there is an official release with OpenSubdiv support. Especially support for multires and sculpt will be complex. A planning for this work and a set of actions still has to be defined.

Nevertheless, Brecht is already on it, and expects to have a first WIP demo of Cycles-OpenSubdiv at Siggraph next week!

Note about the license: OpenSubdivs Apache license is only GPL V3 compatible. Blender is "GPL V2 or later", so that should work fine. However, we do need to check every library we use too, Carve still is GPL V2 only (already connected with Tobias about it).

Thanks,

-Ton-

--------------------------------------------------------
Ton Roosendaal  -  ton at blender.org   -   www.blender.org
Chairman Blender Foundation - Producer Blender Institute
Entrepotdok 57A  -  1018AD Amsterdam  -  The Netherlands



On 15 Jul, 2013, at 8:30, Ronan Ducluzeau aka zeauro wrote:

> Ptex texture color and displacement.
> Dynamic view-dependent surface tessellation.
> 
> 
> On 15/07/2013 00:28, Knapp wrote:
>>> - Good news! Pixar will release OpenSubdiv in GPL-compatible license!
>>> http://graphics.pixar.com/opensubdiv/release_info.html
>> Why do we need/want OpenSubdiv? Don't we have a lot of stuff that does
>> the same thing? For example, subsurface seam strength and Bevel
>> weighted edges and, Dynamictopo?
>> 
>> If we do include it, what is a possible release schedule?
>> 
> 
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