Wednesday, April 21, 2010

Ptex and the Open Source Community

Figure 1: T. Rex with 2694 faces rendered with Ptex. (©Walt Disney Animation Studios)

I decided today to write an article on Ptex, the texture map library that Disney developed and recently released as open source. While this is not fresh news by any means, since it's official release early this year there have been some development in both the commercial and open source worlds.

One of the first applications that support Ptex is naturally Pixar's RenderMan 15.0. After the announcement by Disney in Jan. 3D-Coat was one of the first smaller 3D applications that implimented it within a week, which of course brings to mind that infamous set of images found in the forums.

One of the more interesting images was the texture map itself which looks unlike any map I have ever seen.

The original forum thread can be found here :

However in the open source world it has not caught on quite as fast as expected, in fact to date none of the software in the Blender to Renderman pipeline support Ptex. This is not because of the lack of interest, it is more or less due to development targets. Simply put both Blender and Aqsis are in the process of major rewrites so to implement Ptex into these at this time would divert attention from the important targets in these applications.

Aqsis 1.8.0

Blender 2.5

Does this mean that Ptex will never see the light of day in the open source world? No. In fact if you recall it took some time before OpenEXR was added to Blender, Aqsis and Pixie so while the technology is there currently, it may be some time before it is added across the board. This is not due to developer laziness or as mentioned before, lack of interest (because there is an interest in it from the Aqsis team), it is simply there are more important things to worry about in each application such as functionality, stability and speed.

But all is not lost and it seems that some people have been using workarounds to accomplish usage of Ptex with applications that do not support Ptex, such as Blender.

CG Society Article

Recently there have been some usefull code that has popped up that not only will benefit Aqsis but Blender as well. For instance OpenImageIO (OIIO), which if combined with Ptex and supported in Blender and Aqsis would be something that can be very usefull. OpenImageIO was developed by none other than Larry Gritz, possibly one of the most important figures in the CG industry, from BMRT and Entropy, to the work he did at Nvidia with Gelato. So not only is OpenImageIO a powerfull imaging library but it's also one of Larry's greatest contributions to the open source community.

The /*Jupiter Jazz*/ group has also provided a usefull file cache library called "JupiterFileCache", of which at render time could improve file access speeds, the files can be texture maps, point clouds or other large files to reduce network traffic and disk use. Combined with the OpenImageI/O and Ptex libraries could be a useful benefit for everyone.

The Blender to Renderman project is aware that these recent contributions could have a massive impact on the open source CG industry, so I have a proposal to ALL the developers in these areas : Let's get together and at least come to a common goal to impliment Ptex into these applications as soon as possible. Even if I have to personally spearhead the development and communication between all parties involved, this could very well be one of the most pivotal moments in development after the core rewrites to the applications themselves, in reference to Blender, Aqsis and Pixie of course.

In conclusion it is nice to see more and more large scale studios contributing to the open source community, while the tools or libraries they provide may be small and few, they are greatly welcomed by the community and we are encouraging more of it. One of the goals we are trying to promote is to "play nice", which means that open source software should be able to work well with commercial or proprietary software in terms of file formats, libraries and standards. One of those steps was the addition of OpenEXR (except the minor issue of Blender reading and writing EXR images upside down), hopefully more of the same follows and one of those steps can be the subject of this post : Ptex.

The actual details of Ptex can be found here :

(© Pixar Animation Studios)
(© Walt Disney Animation Studios)

Thursday, April 01, 2010

April Fools! Pixar aquires the source to Aqsis and Pixie in stunning lawsuit

Update : Yes it was a joke ;)

It seems that history repeats itself, as we all remember the sad demise of BMRT and Entropy due to the lawsuit against Larry Gritz by Pixar over patent infringment, or something to that effect. Well recently it has come to our attention that certain projects are being hit with the same lawsuits over graphics technology patents and now Aqsis and Pixe are now no more in the open source domain.
What this means is that the developers have to license the RiSpec from Pixar despite the fact that the code was written from scratch, the patent technology described in papers are so close to the Pixar source code that lawyers are afraid of investment loss. "Aqsis and Pixe, while being open source has this code that infringes on the technolgy Pixar invented, clearly the need to take effort to protect the name and reputation, as well as financial investments, is required" says a source that wishes not to be named for legal reasons.
This seems to be a common trend in the software industry where one technology company sues another over patent infringement, it seems that the open source world is not immune of this legal battle either. This comes as a devestating blow to the community since this means that development on these projects comes to a halt and will require the developers to license the patent, sell the software in order to recoup the license cost and make profit to pay for the subsequent years thereafter.
Already the developers of 3Delight, AIR and RenderDotC have adjusted the pricing to cover the fees with the same legal action, though it is far easier for them since they are commercial products already with established footprints in the industry. The open source community of Renderman users and artists were just starting to establish the valid reason for such tools and on the brink of the dawn the rug was pulled from under us and now we either use the old versions that will remain as is or pay for the next gen versions of our beloved rendering apps.
It is a sad time in our chapter as a whole and we wish the developers of Aqsis and Pixie well as they adjust to the dealings of commercial development. We are only waiting to see if our site gets hit with the same lawsuit over the name RenderMan itself, something also spoken of around the net here and there, so time will only tell if this site exists in the future at all.