RISpec and backend renderers

[Gravedigger]

hei drobby

the rispec descripes the renderman interface which has been suggested as standart for scene descriptions in 3d. unfortunately there hasn't been as many companies interested as hoped so the renderman interface is still not used by that many renderers

the rispec specifies ray tracing as an optional capability because its really is just optional. the REYES architecture does no ray tracing at all but it can be implemented as optional capability witout breaking the renderman standart.

keep in mind pixar has raytracing since 2002. before every reflection has been faked

[Drobby]

Gravedigger (what a morbid name! ;))

I'm so sorry! I thought I had e-mail notifications enabled, unfortunately not - it's only by chance that I've logged in to check things manually.

Edit: Actually, it seems I do have e-mail notifications enabled, but I'm not getting any notifications in my inbox or spam folder - I've encountered this problem before and I think it's a bug with VBulletin.

Thanks for the reply, although I admit I'm still a little unsure of things. Take my first point for example:

This confuses me somewhat, as won't different renderers produce images of different quality?

If reflection is faked using a REYES renderer, but is actually calculated when using a ray tracer, then won't the results look different? If so, then I'm not seeing how the RISpec can be standard if different renderers give different outputs for the same input file?

Thanks,
Drobby

[Gravedigger]

hi drobby

yeah i have this account quite a while already :D
you may call me patrik if you prefer

renderman is a way of descriping a scene. by having a standart maya could simply output a file structured according to the renderman standart and this file could be rendered by every renderer supporting renderman files. this was the idea behind it.

the ri spec descripes how the renderman interface should be structured but they DO NOT write anything about the implementation. its up to the renderer to decide how the image will be created. so yes you will get different results!

but because everything is in the standard like shaders, plugins, texture formats etc those differences shouldn't be that bad. it would rather be differences in the quality


If reflection is faked using a REYES renderer

a REYES renderer does no raytracing at all in the first step. but it does when specified. in the earlier versions there was no raytracing so all reflections have been faked.

hope that helps,
Patrik

[Drobby]

Hi Patrik,

Thanks for the quick reply. From your posts, you seem to be fairly knowledgeable with RISpec, are there any specific resources you could recommend for me to get up to speed with it?

James.

[Gravedigger]

hi james,

unfortunately its a bit a pain to learn renderman in-depth. it has a lot of differences to MR or VRay.

what i can recommend is for example the book: "Advanced Renderman: creating CGI for motion pictures"

its not the newest book but has some very good explanations of the ri interface. it also has great material about shader programming. some very cool production examples etc

i'm very active in the pixar renderman support forum to learn from other threads or to post my own questions when i have problems

Patrik

[Drobby]

Patrik,

Thanks once again for the quick reply - it seems the forwarding e-mails is now failing! :S Is there a renderer you would recommend me getting (I'm not too worried about the cost providing it's clear they're not ripping people off) to play with renderman scripts?

Thanks,
James.

[noizFACTORY]

Patrik,

Thanks once again for the quick reply - it seems the forwarding e-mails is now failing! :S Is there a renderer you would recommend me getting (I'm not too worried about the cost providing it's clear they're not ripping people off) to play with renderman scripts?

Thanks,
James.

You can grab the free version of 3delight. It supports two cores and is free for commercial use too. And its an amazing Renderman.

http://www.3delight.com/en/index.php/step_1

[Drobby]

You can grab the free version of 3delight. It supports two cores and is free for commercial use too. And its an amazing Renderman.

http://www.3delight.com/en/index.php/step_1

Thank you! :)

[Gravedigger]

3delight is a very good choice!
but the user interface in maya is much less integrated

to learn renderman with RSL etc its very nice. the documentation has a lot of information too

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