What is PRMan all about ?

[JamesMK]

Well, I'm no RMan guru, but with some experience in minor productions, I can say this:

PRMan (and other renderman compliant renderers (I'm using 3Delight)) are all about basic workhorse power and customisability.

For instance, if you want to use perfect DOF, true displacement and infinite subdivision surface resolution together with perfect 3D motionblur - what to do? Use a REYES-based RMan renderer (PRMan or 3Delight... not sure about AIR). What happens is that you can render all that without having to wait for several days per frame - in fact, your render will be almost as fast as if you hadn't used any of those features.

If you want to do really weird things that your renderer can't actually do at all - use a renderman renderer and code whatever it is you need. The scene language, RIB, is very flexible, and if you know your math and rendering theory, there's very little you cannot do. Need a totally customised shader? Code your own.

The downside is that you need a good translator. Luckily, Cinemas CineMan is very reliable.

Other downers are pure raytracing and global illumination. These "high-end" rendering technologies are not really fun to use in RMan. GI is quite complicated to set up, not very fast, and raytraced reflection and refraction is painfully slow compared to more "modern" renderers such as Cinema's own AR. On the other hand, renderman implementations of SSS tend to be absolutely beautiful and reasonably fast to render.

EDIT. ADDENDUM:
On a more informal note - there is some sort of intangible, indescribable "feel" to 3Delight renders too... The way surfaces react to lightsources, has a very warm and saturated nature to it. Very hard to describe unfortunately, it's just something that happens while you work with it. Don't know if PRMan is like that too, but it's fairly likely.

[JamesMK]

ADDENDUM 2:
Further more, when looking at the fact that it's usually the solution of choice for big studios (unless they use proprietary renderers a'la Blue Sky) is partly because of the sheer amount of raw access to various aspects of a scene being prepared for rendering. You can poke around as much as you need using shellscripts and custom pieces of software in pretty much any conceivable way. This probably makes it easy to fit such a renderer into a big pipeline. Of course, everything mentioned above boils down to the need for people with some coding skills in order to tap into the real power of these beasts.

EDIT: Oh poop. Pressed 'quote' instead of 'edit'.... ah well... cya later :D

[paulselhi]

So i's not gonna be much use for GI interiors..strnage with so much big clout behind it i would have though GI was an essentil that took high priority


What sort of costs are we talking here ? $1000's £10000's ?

[JamesMK]

A single node of 3Delight will cost you exactly $0. Additional nodes a couple of hundred bucks a pop if I remember correctly.

PRMan is rather more costly. Don't know the exact pricetag though.

And about the lack of GI finesse being "strange", I'd say it's not. You have to consider the typical case where RMan is used - VFX shot layers, full CG animations a'la Pixar etcetera... GI hasn't really become a technique to rely on, as these guys do things very differently. Ambient occlusion and environment maps... that seems to be the main tricks if you look at ILM for instance. Does the job reliably and on budget in terms of rendering on time and so forth.

[dann_stubbs]

A single node of 3Delight will cost you exactly $0. Additional nodes a couple of hundred bucks a pop if I remember correctly.


the cost for C4D users is the price of the production bundle - which after nearly a year i still don't know the price of. so only beta testers and and maybe a large studio or two may have the maxon exporter for PRM. (is it named cineman? - i've not been following it much lately)

lot's of potential for external render engines for C4D - just all seem to fall through in one area or another... (i.e. unfulfilled promises of FR2 and M~W, lack of info on C4D PB and price, and VRAY just is too early in to know yet)

dann

[stew]

PRMan or other renderers of similar programmability are almost more like a "renderer construction kit" than just renderers: For example, before PRMan got raytracing people were plugging in other renderers (like BMRT) as "ray servers" to handle the raytracing. Users wrote their own point clouds for SSS. In that regard, the limits of PRMan are usually not the renderer itself but rather the user's limits.

Also, it's very robust in terms of what scene sizes it can handle. The Reyes algorithm, the texture management and bucket rendering keep memory usage down even with lots of primitives in the scene.

The obvious downside is that the flexibility comes at the price of requiring the user to understand how it ticks. There is no magic GI checkbox in PRMan that adds indirect light and caustics to your scene automagically. Instead, there are functions that you can use to write your own indirect light and caustic shaders.

[Filip]

On a more informal note - there is some sort of intangible, indescribable "feel" to 3Delight renders too... The way surfaces react to lightsources, has a very warm and saturated nature to it. Very hard to describe unfortunately, it's just something that happens while you work with it. Don't know if PRMan is like that too, but it's fairly likely.

I've been playing with 3Delight a lot lately and I think I know what you are reffering too. I believe this is because 3Delights by default uses a specular model wich is more accurate than the standard phong model. While this looks nice, the really cool thing according to me is that it's easy to replace this illumination model by basically anything you want by writing custom shaders. So you can get any look you want!

[LucentDreams]

So i's not gonna be much use for GI interiors..strnage with so much big clout behind it i would have though GI was an essentil that took high priority


What sort of costs are we talking here ? $1000's £10000's ?

Most Highernd TD's will roll their eyes at GI, unless specificlaly for HDR IBL and often if they are doing that they are using Mental Ray instead. A Renderman TD is morelikely to have some crazy ambient occlusion passes and a whackload of wlel placed lights and bounce lights. Faster, more specific control. GI may be the demand of your candy coated renderers like Final Render and VRay, but not PRman and many other renderman compliant renderers. FR and Vray are good for high quality images for simpler scenes, and yes I mean a lot of architectural scenes as simpler ;) Imagine a shot form pixar or ILM compared to what you see going on in any architectural render. the insane amonts of particles, fluids, crowds etc. With cinema and writing our RI points, I've been able to render complex dust clouds in 10's of seconds in what woudl take cinema or more so pyrocluster ages, Stormtracer would be the closest comparison.

Where most reyes renderers especially PRman and AIR take their lead is memory handling and management, not to mention manual optimization. AT siggraph last year the PRman renderman Usergroup had a presentation on the bridge scene fro Fantatic four in which the initial renders of just ambient occlusion were taking 116 hours per frame, and was able to get that down to some 40 minutes if I remeber right.

Reyes renderers aren't as straightfowraward as your typical raytracer, reflections are accurate simulation unless you have raytracing in your reyes renderer, bac when they did Toystory there were no true reflections at all, the reflections you see in Buzz's mask are all very complex shaders.

Last few years PRmans' develpment has been a lot more focused on GI and raytracing as systems and code gets fast enough to make these actually more suitable for a lot of tasks. A hybrid reyes/raytracer is a powerful tool. I believe 3Delight is a hybrid as well, AIR is a renderman compliant renderer, but its actually jsut a raytracer not a reyes renderer. However its had a lot more focus on things like memory management ands cuh which is why its such a popular renderer for film.

best way to put PRman though is that its like maya, its defintiely not the best or easiest right out of the box, but especially in a highend pipeline, its the most customizable, flexible and reliable.

[dann_stubbs]

best way to put PRman though is that its like maya, its defintiely not the best or easiest right out of the box, but especially in a highend pipeline, its the most customizable, flexible and reliable.


http://highend3d.com/news/software/154.html

sure makes the unavailability of the C4D plugin a bit more frustrating for some users i would guess...

dann

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