View topic - Looking for some renderer research information :)

Looking for some renderer research information :)

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Looking for some renderer research information :)

Post Sat May 14, 2011 2:16 pm

Hi hi.

I'm looking for some possible research topics for a dissertation, and I'm considering looking into other renderers.

I guess 'Hollywood' people making 'Spiderman' or 'Up' or some vfx heavy blockbuster would be more inclined to look at the likes of 3Delight, Maxwell and Arnold. Can anyone point me to some useful research literature or more general information on this kind of rendering?

I guess the ability to create custom shaders is a good thing, along with fast motion blur, dof and fur, but what else would persuade me to use them and why would I not consider, eg, VRay or Yafaray for big budget rendering?

Also, current trends seem to suggest single pass ray tracing is gaining popularity. Is post process compositing separate passes a legacy of a lack of render speed/features, such as GI?

Thanks for any and all assistance and suggestions :D
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stoneage
 
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Re: Looking for some renderer research information :)

Post Sun May 15, 2011 9:50 am

Hi Stoneage

I can not speak for other engines since I have never used them.

YafaRay is a montecarlo raytracer. Montecarlo is an integration method for generating the sampling of the scene lighting. This integration is not only used in pathtracing, it is used whenever a number of discrete samples is generated to aproximate lighting, for instance in direct lighting mode (arealight, background lighting) and indirect lighting (pathtracing, final gather).

Path tracing is a relatively old method. It works very well when most of the path rays find a light source ¡n the first and second bounces, that's why works very well with big arealights and background lighting. If many or most of the path rays don't find a light source in the first bounces, and they need to perform more bounces to find it, then there is going to be variation, which means noise. Getting rid of noise in path tracing is not easy, to halve the noise you need four times more samples. Path tracing is almost useless for caustic effects, as the reflection and refraction of rays make it even more difficult for the path rays to find a light source.

The main advantage of path tracing is that it is very consistent and predictable, it is not going to give you surprises or light leaks. Besides, the high frequency noise path tracing gets to produce is more compatible with animation and antialiasing, because it is less noticeable to the human eye than low frequency (big patches) noise.
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Samo
 
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Re: Looking for some renderer research information :)

Post Mon May 16, 2011 9:22 am

For info about Renderman you can find SIGGRAPH courses in pdf format here (warning: most of the material is very techy).

I guess the ability to create custom shaders is a good thing, along with fast motion blur, dof and fur, but what else would persuade me to use them and why would I not consider, eg, VRay or Yafaray for big budget rendering?


What have the Romans ever done for us? :D

But seriously, I don't think you could use Yafa for the big budget rendering you mention. Lack of passes, customization like disabling shadows, caustics for separate lights, shadow-catching materials, etc., all the stuff that VRay has. Let's not even talk of the full pipeline programmability Renderman implementations offer... Yafa is a good niche 'product' and the niche is archviz & product design, where postpro composition doesn't play a big role.
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_Mo_
 
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Re: Looking for some renderer research information :)

Post Mon May 16, 2011 5:13 pm

Multi CPU optimised Ray-tracing is the standard for movie industry today. This 2 videos will show you Why Sony Pictures works with Arnold and not with a Reyes/Renderman engine

http://vimeo.com/15878348
http://vimeo.com/16155555

"Power tends to corrupt, and absolute power corrupts absolutely. Great men are almost always bad men."

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condar
 
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Re: Looking for some renderer research information :)

Post Tue May 17, 2011 3:06 pm

Thanks guys, that all looks like useful information. Now for the studying :)



:D

I still would like to use Yafaray for film work, though mainly because I don't currently have the cash to spend on other software. We have recently had V-Ray installed at the university, but they are still running all the labs on 32 bit Windows, so you can imagine how often Mental Ray crashes on those machines. V-Ray is more stable(and runs on the 64 bit render farm - 32 cores and 48 GB RAM :D), but I still find Yafaray very useful, especially now that it is portable; though it is not available on the render farm. Ah, decisions, decisions.......
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stoneage
 
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Re: Looking for some renderer research information :)

Post Wed May 18, 2011 7:48 am

If you have free access to Vray then it's a no-brainer, IMO. You can still use / learn Yafaray at home, while learning Vray at univ. This way you'll be an expert in both and able to propose useful improvements to Yafa. :)
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_Mo_
 
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Re: Looking for some renderer research information :)

Post Wed May 18, 2011 7:54 am

_Mo_ wrote:If you have free access to Vray then it's a no-brainer, IMO. You can still use / learn Yafaray at home, while learning Vray at univ. This way you'll be an expert in both and able to propose useful improvements to Yafa. :)


Quoted for agreement.
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Samo
 
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