Comments on: Manifold exploration talk now online

By: Ian

Ian — Sat, 29 Sep 2012 11:15:42 +0000

That’s interesting…

General Purpose GPU sounds like a bit of an oxymoron to me anyway, because the more general purpose they become, the more like a CPU they will be.

By: Wenzel Jakob

Wenzel Jakob — Fri, 28 Sep 2012 20:20:53 +0000

no, those are just drawn in Illustrator.

By: TwinSnakes007

TwinSnakes007 — Fri, 28 Sep 2012 19:44:31 +0000

So, I’m assuming those cartoon outlines I’m seeing in the 4.0 docs are made with this 2d renderer? Or do you have some more surprises?

By: Samuel

Samuel — Thu, 27 Sep 2012 15:49:19 +0000

Okay that makes sense to me. Thanks for the answer

By: Wenzel Jakob

Wenzel Jakob — Wed, 26 Sep 2012 20:29:02 +0000

The performance advantages are exaggerated and comparisons against CPU implementations are often outrageously unfair (e.g. showing a benchmark between a naive single-threaded exact CPU implementation and heavily optimized approximate GPU code).

The programming model and architecture also limit the complexity of algorithms that can be implemented on them. Certain very “random” methods like MLT are just not all that well-suited for GPUs, which rely on coherence between independent pieces of work. This is in addition to the incredible amout of work that it would take to even get the algorithm working on a GPU (and maintaining that over the next years).

In a few years, the architecture and programming models may have evolved to be more useful. But at this point, a project like Mitsuba has little to gain from them.

By: Samuel

Samuel — Wed, 26 Sep 2012 19:22:40 +0000

Okay thank you just wondering. I have a laptop with a fairly good GPU so I was just curious about it. May I ask why it is over hyped?

By: Wenzel Jakob

Wenzel Jakob — Sun, 23 Sep 2012 00:15:10 +0000

There are no plans to incorporate GPU rendering (other than the preview) in the near future. This is something that’s massively over-hyped in my opinion.

By: Samuel

Samuel — Sat, 22 Sep 2012 23:11:22 +0000

Can’t wait for the next release of Mitsuba, what other improvements are going to be made other than the previewer and adding manifold? And is their a plan for using GPU for rendering? Or is gpu just something a third party would have to do?

By: Yoran

Yoran — Sat, 22 Sep 2012 19:27:50 +0000

Haha amazing, I knew it was something special, as I had never seen 2d raytracing like this, great job 😀

By: Dillon Bailey

Dillon Bailey — Fri, 21 Sep 2012 20:31:56 +0000

Wenzel,
That is awesome.
You are a true CGI Architect (a 2d raytracer to create a visual to illuminate your 3d raytracing algorithms? I love it)

By: Wenzel Jakob

Wenzel Jakob — Fri, 21 Sep 2012 18:45:41 +0000

Its only purpose was to produce these figures, so I don’t think it will be of much use to other people. For something like that to be made available, it will need documentation, a proper user interface, etc..

By: TwinSnakes007

TwinSnakes007 — Fri, 21 Sep 2012 18:32:41 +0000

Really? How does your 2D raytracer perform? I’d imagine it’s very fast. Can we play with it?

By: Wenzel Jakob

Wenzel Jakob — Fri, 21 Sep 2012 00:45:32 +0000

Hi Yoran,

the 2d demo explorations were made with a custom PostScript ray tracer that I wrote. It loads vector graphics designed in a program like Illustrator and then traces rays against the Bezier splines. I got a bit carried away 😉

Wenzel

By: Yoran

Yoran — Thu, 20 Sep 2012 18:51:36 +0000

Wenzel, amazing stuff, you manage to explain it
in a way that even for someone like me, lacking the mathematic knowledge, its understandable.
Can I ask what you used to make the 2d demo explorations?

By: Reynante M. Martinez

Reynante M. Martinez — Wed, 19 Sep 2012 07:06:15 +0000

Very impressive work, Wenzel! I’m really looking forward to using Mitsuba as my production tool. Hoping to see more. Thanks for sharing.

-Reyn

By: Ejnaren

Ejnaren — Sun, 16 Sep 2012 11:06:33 +0000

Very nice work WJ.
Extremely clear and understandable. Mitsuba is such a cool project and as Konstantins says, it is very nice that you share your findings and explorations so that we too can learn from it!

By: Ian

Ian — Fri, 14 Sep 2012 19:47:23 +0000

“I’m only afraid that it is too complicated to make it’s way to open mass uses like of Blender” – but Blender can communicate with Mitsuba so it is not a problem, all that needs to happen is inter-program communication needs to improve.

By: Konstantins

Konstantins — Fri, 14 Sep 2012 19:41:58 +0000

It’s warming to know that 3D is still evolving with such leaps. It’s also amazing to know the initiative is not born inside commercial, kept in secret offices. I’m only afraid that it is too complicated to make it’s way to open mass uses like of Blender.