Marcos, the creator of the Arnold renderer in use at Sony Pictures Imageworks was recently interviewed. Fun read. In an email conversation with him, he pointed out some recent papers he was directly and indirectly involved with. They too are worth reading if you are into raytracing.
Physically-Based Shading and Lighting at SPI
Siggraph 2010: Course on Global Illumination
And for added fun, here are some wayback renders done in the early versions of Arnold for 3dsmax. Some of which I did;)
Tuesday, August 31, 2010
Vray vs. Mental Ray
I have gotten some requests to expand on my transition to Vray so I'll take an opportunity to do so.
What sold me on Vray during early tests was its general speed at handling GI renders. Without getting into specific benchmarks, it was pretty clear to me that Vray had a substantial speed gain in complex GI scenes. The other major influence was "The Nederhorst" settings, as they have come to be known around here. These settings leverage Vray's powerful Deterministic Monte Carlo (DMC) sampler. The general idea is to minimize the amount of settings you need to tweak to affect your render quality. In production, as in life, simpler is better.
The specifics are here, but the general method is to tell Vray's sampler to be fully adaptive, so it will refine samples only in areas that need it, based on a simple contrast threshold setting. This sped up our productions significantly, as we needed to do much less tweaking to get quality renders.
This is what prompted the switch. Since then, Vray has grown in features, and I can confidently say, that it is now better integrated into Maya than MentalRay. It has added hair rendering, will render its own fur, fluids, particles, and has a much easier-to-use pass system. We consistently spit out custom channels for material id, AO, Z, normals, and other custom textures, in one neat-and-tidy render. Vray negates ever having to touch Maya's renderpass system, and makes our lives much nicer.
Another benefit is in Vray's handling of "Linear Workflow." With a click of a button, Vray will adjust all input colors/textures to any gamma you like... thus compensating for the 2.2 baked-in gamma of most textures and colors in Maya. We really don't even think about linear workflow, as we are always in it. Using the Vray Framebuffer, you can dynamically switch on sRGB compensation, to adjust your linear image to monitor-space for quick evaluations. You can plug in your own LUT, you can quickly add your own curves in the framebuffer to imitate what color treatments you may apply later. It adds linear workflow to Maya in the way it should always have been done.
Another great addition is the easy-to-use distributed rendering. We do a lot of hires print images. 5-15k. So no GI renderer on a single machine will be speedy. With a dedicated set of machines on a farm, you can toggle a button and harness many machines to attack a single frame. 5 k renders done in minutes, as buckets race across the screen. While MR standalone will allow you to do this as well, you'd have to invest the extra bucks for that, and Vray is still faster and easier to set up.
Lastly, VrayRT has appeared in beta form, and is now changing the way we light once again. We have already put it in production on our latest automotive renders, with great results. VrayRT-GPU may again change things in just a few more weeks. We look forward to using the additional horsepower already in our towers.
So, that's the sales pitch;) Really, it has been a great ride in the last year, and I thank Chaos Group for working so hard on this product.
What sold me on Vray during early tests was its general speed at handling GI renders. Without getting into specific benchmarks, it was pretty clear to me that Vray had a substantial speed gain in complex GI scenes. The other major influence was "The Nederhorst" settings, as they have come to be known around here. These settings leverage Vray's powerful Deterministic Monte Carlo (DMC) sampler. The general idea is to minimize the amount of settings you need to tweak to affect your render quality. In production, as in life, simpler is better.
The specifics are here, but the general method is to tell Vray's sampler to be fully adaptive, so it will refine samples only in areas that need it, based on a simple contrast threshold setting. This sped up our productions significantly, as we needed to do much less tweaking to get quality renders.
This is what prompted the switch. Since then, Vray has grown in features, and I can confidently say, that it is now better integrated into Maya than MentalRay. It has added hair rendering, will render its own fur, fluids, particles, and has a much easier-to-use pass system. We consistently spit out custom channels for material id, AO, Z, normals, and other custom textures, in one neat-and-tidy render. Vray negates ever having to touch Maya's renderpass system, and makes our lives much nicer.
Another benefit is in Vray's handling of "Linear Workflow." With a click of a button, Vray will adjust all input colors/textures to any gamma you like... thus compensating for the 2.2 baked-in gamma of most textures and colors in Maya. We really don't even think about linear workflow, as we are always in it. Using the Vray Framebuffer, you can dynamically switch on sRGB compensation, to adjust your linear image to monitor-space for quick evaluations. You can plug in your own LUT, you can quickly add your own curves in the framebuffer to imitate what color treatments you may apply later. It adds linear workflow to Maya in the way it should always have been done.
Another great addition is the easy-to-use distributed rendering. We do a lot of hires print images. 5-15k. So no GI renderer on a single machine will be speedy. With a dedicated set of machines on a farm, you can toggle a button and harness many machines to attack a single frame. 5 k renders done in minutes, as buckets race across the screen. While MR standalone will allow you to do this as well, you'd have to invest the extra bucks for that, and Vray is still faster and easier to set up.
Lastly, VrayRT has appeared in beta form, and is now changing the way we light once again. We have already put it in production on our latest automotive renders, with great results. VrayRT-GPU may again change things in just a few more weeks. We look forward to using the additional horsepower already in our towers.
So, that's the sales pitch;) Really, it has been a great ride in the last year, and I thank Chaos Group for working so hard on this product.
Monday, May 10, 2010
First Vray tests (from 1 year ago)
So, I haven't been updating very much in the past year (sorry), but here's some new info. As mentioned, I've switched to vray. This was the first thing I made while testing it (around April 2009).Some things to note about this image:
It is an "impossible" lighting setup in the real-world, and when we are tied up in physically accurate lighting, we need to remember that lighting direction doesn't always have to follow real-world rules. The goal of this image was to recreate a particular composite of images where lighting was tuned for each specific part of the interior then combined in photoshop. The overall image works, even though lighting cues/directions are all mixed up.
There are about 30-40 rectAreaLights in the scene, split up into "zones" and there are lots of light exclusion/linking going on to keep one zone from affecting another zone. Zones were broken up into seatLeft, seatRight, Steering Wheel, Side Door, Shifter, Dashboard, and Dashboard Central. This render is just about raw from Vray, and very little has been done to it other than some retouching and minor CC.
I wouldn't call it totally finished, as there are some texture problems, and could use some post love and color grading, but this served as a great test to see how our switch to vray might go. I took about one week to produce this image, from having never used vray before. I'd say this image has some very inefficient render settings, since I wasn't quite versed, but the quality and relatively low learning curve (from MR) convinced us to make the switch.
Friday, February 12, 2010
SLIK Studio Lighting Tools
Here's a link: SLIK
Now, while this seems cool, it feels a bit overkill. Here's what I like:
- ies profiles for each light. That is cool, and useful.
- high detail for the illuminant surface
- a model library of lights for when you need them.
Now I'll discuss what I think is wrong. The obvious being... that's a lot of heavy geometry for a scene where I'd prefer my heavy geo be in my product. This seems like a way to slow down fluid production. Friendly controls are ok, but really, how hard is it to adjust the intensity of a light in the lights attributes? Do I really need on-screen controls for this cluttering up my workspace?
Yes, I get that the end product could be a simple hdri... but why? Why substitute the control of individual lights for an hdri when you don't have to?
Here's a suggestion for an alternative. I wish someone would produce this so I could buy it, since I don't have time to make it all myself (hint hint, wink wink). Simply photograph lighting equipment in HDR. Then you have an accurate image (with all the detail and folds, and tape marks, and whatever floatsYerBoat). Place those images onto your area lights in MR/Vray and have fun. Light (geometrically speaking), easily adjustable, no need for models beyond cards and lights. For direct lights, ies files would be great.
SLIK seems fun, but it wouldn't really help production fluidity for me, and I do a lot of product imaging. It would be cool if you need to render the guts of a photo studio tho;)
Now, while this seems cool, it feels a bit overkill. Here's what I like:
- ies profiles for each light. That is cool, and useful.
- high detail for the illuminant surface
- a model library of lights for when you need them.
Now I'll discuss what I think is wrong. The obvious being... that's a lot of heavy geometry for a scene where I'd prefer my heavy geo be in my product. This seems like a way to slow down fluid production. Friendly controls are ok, but really, how hard is it to adjust the intensity of a light in the lights attributes? Do I really need on-screen controls for this cluttering up my workspace?
Yes, I get that the end product could be a simple hdri... but why? Why substitute the control of individual lights for an hdri when you don't have to?
Here's a suggestion for an alternative. I wish someone would produce this so I could buy it, since I don't have time to make it all myself (hint hint, wink wink). Simply photograph lighting equipment in HDR. Then you have an accurate image (with all the detail and folds, and tape marks, and whatever floatsYerBoat). Place those images onto your area lights in MR/Vray and have fun. Light (geometrically speaking), easily adjustable, no need for models beyond cards and lights. For direct lights, ies files would be great.
SLIK seems fun, but it wouldn't really help production fluidity for me, and I do a lot of product imaging. It would be cool if you need to render the guts of a photo studio tho;)
Monday, October 5, 2009
Linear Light Talk by MasterZap
As posted by Master Zap on his blog: here
He goes into some technical details of the linear-space lighting process. There are some really good explanations for what is really going on behind the scenes, and I highly recommend a listen. FXGuide has my utmost fandom at giving him some time to talk. Here is a more direct link to the podcast.
He goes into some technical details of the linear-space lighting process. There are some really good explanations for what is really going on behind the scenes, and I highly recommend a listen. FXGuide has my utmost fandom at giving him some time to talk. Here is a more direct link to the podcast.
Sunday, September 13, 2009
Vray Switch
Hey folks, I have some news. I've been testing Vray and RT over the last few weeks. And now that Vray for Maya is a reality, I can seriously consider switching. While I love 3dsmax for many things, I still feel Maya is required for many tasks, and wouldn't be without it in production. I'm getting pretty comfortable with Vray in both Max and Maya, and have to say it is a big step up from Mental Ray, which has unfortunately languished for the past few years with few useful updates.
There are things I can do in Vray, that I just couldn't accomplish properly with MentalRay. Many may argue, you can do the same quality work in MR, and short of true DOF and MB in reasonable time, I would agree. However, the man-hours required to do the same level of work are vastly different. Vray's unified DMC sampling (global glossy settings) and many other features I'll discuss later, make setting up complicated realistic settings very easy. I have already done work with vray that I doubt I could have done in twice the time in MR. saving caches, baking, importance sampling in image and area lights... the list goes on, and I have to say I wish only that I had jumped in earlier. More soon.
BTW, due to a few Russian spam comments, I've turned on posting administration. Thus your comments may take a day to show, since I have to approve them. But I'll generally let any post through that isn't spam. Even if you hurl insults;)
There are things I can do in Vray, that I just couldn't accomplish properly with MentalRay. Many may argue, you can do the same quality work in MR, and short of true DOF and MB in reasonable time, I would agree. However, the man-hours required to do the same level of work are vastly different. Vray's unified DMC sampling (global glossy settings) and many other features I'll discuss later, make setting up complicated realistic settings very easy. I have already done work with vray that I doubt I could have done in twice the time in MR. saving caches, baking, importance sampling in image and area lights... the list goes on, and I have to say I wish only that I had jumped in earlier. More soon.
BTW, due to a few Russian spam comments, I've turned on posting administration. Thus your comments may take a day to show, since I have to approve them. But I'll generally let any post through that isn't spam. Even if you hurl insults;)
Thursday, June 18, 2009
Lighting Blocking
Just a quick post to remind people I still exist;)
Thought I'd share a working method for lighting if it weren't already obvious to you (It probably is). Just like animation, blocking is an important stage. Roughing out light positions, intensities, etc. should be as fast and interactive as it can be. When dealing with say, and interior render with GI, bounces, and such, fast seems to be an oxymoron. It can be bearable, and even fun if you optimize your scene for it.
Just like blocking an animation, you don't need every feature turned on. While you can always tune your render settings, that's not what I'm talking about. I leave my FG and AA at medium. Say 75FG samples, 20 interpolation and global AA at 0 or 1 to start. Beyond that, the biggest slowdown in a render are the shaders. So use something very simple to block out lighting. a light grey mia or even a lambert. Such materials will render much faster.
My workflow is to create a lightingBlocking renderLayer with a material override to the mentioned grey material. Start blocking lights and render iteratively, or use IPR. Blocking lights without the interference of material color is useful in 2 ways. First in speed as mentioned, but also to judge values and lighting ratios more easily. Here's an example of a blocking render for a recent job. Some clients are receptive to seeing this stage, some are not. But if nothing else, it is helpful for you to make creative judgements.
This is closer to a final blocking. In earlier iterations the bed was too dark, as was the hall. So a window was added to the hall, and a lamp (omni light) was placed at the bedside to fill the bed a bit. Ulimately, one more light was placed in the hall, and minor tweaks to some settings were required once full color and materials were added.
Thought I'd share a working method for lighting if it weren't already obvious to you (It probably is). Just like animation, blocking is an important stage. Roughing out light positions, intensities, etc. should be as fast and interactive as it can be. When dealing with say, and interior render with GI, bounces, and such, fast seems to be an oxymoron. It can be bearable, and even fun if you optimize your scene for it.
Just like blocking an animation, you don't need every feature turned on. While you can always tune your render settings, that's not what I'm talking about. I leave my FG and AA at medium. Say 75FG samples, 20 interpolation and global AA at 0 or 1 to start. Beyond that, the biggest slowdown in a render are the shaders. So use something very simple to block out lighting. a light grey mia or even a lambert. Such materials will render much faster.
My workflow is to create a lightingBlocking renderLayer with a material override to the mentioned grey material. Start blocking lights and render iteratively, or use IPR. Blocking lights without the interference of material color is useful in 2 ways. First in speed as mentioned, but also to judge values and lighting ratios more easily. Here's an example of a blocking render for a recent job. Some clients are receptive to seeing this stage, some are not. But if nothing else, it is helpful for you to make creative judgements.This is closer to a final blocking. In earlier iterations the bed was too dark, as was the hall. So a window was added to the hall, and a lamp (omni light) was placed at the bedside to fill the bed a bit. Ulimately, one more light was placed in the hall, and minor tweaks to some settings were required once full color and materials were added.
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