Brick map system like renderman for Global and Abiant Occlusion…
Micro polygon displacement as Renderman…
If you wish…
Is irradiance map using this system ???
Bye…
It sure is.
Displacement IS taken into full account by GI, provided the displaced details is large enough to grant it some attention from the GI solution, or that the method used to calculate GI is accurate enough.
This, if i got the spirit of your message right…
EDIT: i think i didn’t , after all, lol
Lele
Re: Brick Map and Micropolygon Displacement as Renderman
You will find that the irradiance map system that Vray has is so efficient at finding good solutions that you don’t need brickmaps or even ambient occlusion. You will throw it all away and use straight GI will color bouncing. It is like asking for a bigger hand crank on your car to start it when Vray is offering a you an electric starter.
As far as micropoly is concerned. Two things to note.
1 - Renderman is a Reyes rendering engine that converts everything to micropolies… at a shading rate of 1 every pixel is a polygon… this is a very different way of working. So the concept of a micorpolygon in the renderman way is completely wrong for rendering engines like mental ray, vray, etc… Reyes rendering is probably the downfall of renderman’s raytracing as it ends up having do with so many polys. While it is fine and good for scanline (which is what renderman is) it is a nightmare for raytracing.
2 - Vray does its own version of micropoly displacement as well as Subd. It can subdivid the geo in world space or screen space. When doing it in screen space, it is similar to micropoly system (conceptually) of renderman. Mentalray does something similar.
chris, then how is it that render man is so fast with mtd? or is it becuase there is no raytracing going on?
maybe because it’s reyes, so it’s very efficient discarding what it doesn’t need.
In fact it does seem to crawl when any raytracing is enabled, also because of the “rejection” being a lot less efficient (relfection, refractions, raycast shadows and so on).
Or so i gather 
Chris has definitely more first hand knowledge than I do.
The Mr solution, though, it’s extremely fast and very good especially when mixed with moblur.
And as for Rman is under the scanline realm.
It’s a lot faster when combined with raytracing, though, than Rman.
Probably because Mr developed a solid raytracer/scanline hybrid first, and then added on the screen-space micropolys, rather than the other way around like for Rman.
Lele
Oh yeah… no raytracing on that or in the subD or nurbs either. Builds the MP as the bucket goes into it… Keep in mind that you need to take into account the displacement bounds because of that. All things considered the raytracing in renderman is very fast, it is the fact that it needs to do it with a reyes architecture in my mind that is killing it. Things like AO and Brickmaps have to be reverse engeneered into the process just to be able to do both.
so having said that, how would you make photo realistic lighting in rman?
like i mean match daylight lighting reflections etc?
Most rman lighters tend to avoid it where possible by using reflection maps that are as close to the scene they’re mimicking as possible but if there’s obvious contact between objects then they resort to raytracing. They us a kind of ibl technique too where they use a blurred reflection map of the environment as one pass and use an ao pass to control it. This is then blended with key / rim light passes to build up the effect.
in other words, pain and suffering…
For sure… I have used this analogy a lot, but lighting in renderman is much more like paint by numbers while lighting in with GI and IBL is a lot more light photography or cinematography.
Quite some analogy, Chris.
Why not thinking of RMan like that old, rich, bitchy uncle we’d all want to be safely stowed in the closet for good, but that keeps banging loudly at the closet door to reclaim some more fresh air? 
I should stop wasting myself on saturday nights, i think… :lol:
Lele
Re: Brick Map and Micropolygon Displacement as Renderman
This is not a very good idea for a raytracer. Further on, V-Ray already does a fairly good job at displacement.
Brick map system like renderman for Global and Abiant Occlusion…The method used by V-Ray does a somewhat better job at preserving details in the GI, whereas brick maps tend to blur things quite a bit - which is one of the reasons it is suggested to use it for secondary bounces only.
Best regards,
Vlado
excuse me, but what is brick map?
Seems to be another lighting caching method like irmaps - https://renderman.pixar.com/products/news/rps12.0\_announced.html
renderman is grean an all…
but imo anything thats done in it can be done just as well in vray.
I’d agree with you. The rib file format and the shader language does seem to be very handy though - Admittedly I dont work for a facility that’s big enough to take advantage of any of those features so it’s not an issue. It’s definitely a hinderance for me getting jobs in other visual effects facilities though since max can’t integrate into big pipelines in this way.
well, for instance in our studio (image-engine) they are looking to switch renderers, and one of the suggestions was render man. However, no one knows render man well enough to be able to start a solid production of of it, and this is quite common. What needs to be done, is usually a studio will hire couple of render man programmers to help initialize rman and develop shaders, scripts etc, which is quite costy. Not to mention the price for licensing and etc. And chris will agree with me im sure, as i recall him explaining the pass procedure for movie stealth, where custom scripts had to be written to automate pass output.
Such situation precists not only in rman however. At present we are stuck with mental ray, and mental ray in maya suffers i think the most. Bad bad intergration…
At one point it took me 5 hours to output (not render) 5 passes. Because I had to do it manually. After that we have developed a dynamic shader library also via scripting to make such operation possible in 5 min not 5 hours. Where as in vray its all already there.
Vray is unmatched in such cases.