Rendering Fundamentals General

Maya, Renderman RIS

Installing Renderman

This video is for v20 but the process is much the same for v21…

 

1. Go To The Non Commercial Renderman Page And Follow Prompts
2. Create a Renderman Forum Login
3. Download and Run the Temp Installer
4. Login With Your Renderman Forum Login
5. Choose Maya Version (“Click Show All”)
6. Install From The Internet Installer
8. Open Maya
9. Open the Plugin Manager, Turn On Renderman
Windows > Settings And Preferences > Plugin Manager > (scroll down) > Renderman_For_Maya > check both on

 

Renderman v21

Renderman has just had a huge makeover in v21 released in Nov 2016, and much of the renderer has changed. This looks like a great release.

**Note: Be careful installing the new version as you cannot install the old version with the non commercial installer!!

Most of this page is for v19/v20, but with the changes in v21 many things will be similar but might have changed slightly.

This page is in no particular order, it is a dump of notes and things to look out for in Renderman.

 

Upgrading v20 scenes to Renderman v21

To upgrade a old Renderman scene you must simply remake all lights as they’ve completely changed.

The old lights are still found in the scene but will not work. So you should create new lights and match them for translation rotation and scale. Then copy settings like intensity and if spot lights create pxrDiskLights and match those instead then find the cone angle and softness settings and match those.

In simple scenes upgrading lights isn’t much of a problem and the intensity settings on new lights matches pretty well.

Although you cannot make old pxr shaders in v21 the old shaders are still supported. Disney shaders not tested. You should also upgrade these shaders if you need future compatibility. But they should work fine in v21.

AOVs such as mattes seem to be ok too.

 

Correct Installation of the v21 Presets

Pixar’s “Preset Browser” is great in v21 but to install it correctly you should move it to a new location so you can save your own settings. This is highly recomended. After installing Renderman move the library with these steps…

1. Find the library location by opening the Preferences Window
Prefs Window > Settings > Renderman > Preset Browser
2. Go to that location on your system and manually copy the folder to a new location I use…
2017/modules/RenderManAssetLibrary
3. Close Maya
4. Open the maya .env file
maya2017/maya.env
In a txt editor and add the line. This is a single line…
RMAN_ASSET_LIBRARY = /Users/andrewsilke/Library/Preferences/Autodesk/maya/2017/modules/RenderManAssetLibrary
5. Start Maya
Full documentation is here, (scroll down)
Preset Browser Info

 

v21 New Shaders

The shaders are now called PxrSurface and PxrLayerSurface. They look great, they are a monolithic/uber shader, that means they do everything, glass, sss, metals, plastics, cloth etc.
It also looks like there’s some Disney shader stuff in there, so you can go artistic mode (aka Disney Shader) and might be good for importing Substance Painter textures.
The SSS now has various modes and is much simpler.
Subsurface Shaders Video

 
Also see…
Gun Shader Tutorial

 

v21 Portal Lights

Portal lights seem very useable for interiors, this is quite exciting, from a quick test they looks quite useable! 🙂
Portals are found under PxrDomeLight (right click that icon)
Documentation…
PxrPortalLight – RenderMan – Renderman Documentation

 

v21 Sampling Changes

Looks like the sample settings may need adjusted defaults now, I was testing the portals and renders cut out too early even at 1024 max samples, on a quick test you can up the min samples to up the quality, or play around with the new setting, “dark falloff”. This looks like it’s affecting renders a fair bit by undersampling the darker areas of your scene. This was my case as I was exposing up after rendering.

 

What are Integrators?

Integrators are like little subRenderers inside of RIS. Different integrators can be used depending on what you’re rendering, and you can only use one at a time, so think of it like a renderer inside of a renderer. (RIS actually stands for Rix Integrated Subsystem).

As RIS grows, more and more integrators may be added as new technology becomes available.

At the moment there’s 2 main Integrators in RIS and they are found in
Render Settings (shift 5) > Sampling (or IPR Sampling) > Integrator > Integrator

The two main Integrators are
1. Path Tracer
2. VCM

 

Path Tracer

Advantages: Fast and Good Quality
Disadvantages: Less Accurate Caustics and Bounce Lighting

The Path Tracer algorithm is the default “Integrator” and there’s little need to change it. It produces lovely renders particularly in outdoor scenes but also for interiors as well. You’ll use this almost all of the time.

The Path Tracer is a single path tracer, and not a bidirectional path tracer like VCM.

 

VCM

Advantages: Superior Quality especially in Caustics and Bounce Lit Interiors
Disadvantages: Slower, much slower in many examples, more noisy.

VCM is an optional “Integrator” and has superior rendering in the case of caustics and indirect bounce light. It is a much slower render generally speaking. So only use if you’re happy for long render times or if you aren’t getting results with the Path tracer (in some rare circumstances). Can be used more for stills with overnight renders or you have a large render farm for rendering animation.

VCM’s selling point is that it’s a bidirectional path tracer, (see page about raytracing) as Pete Moxy says in regards to the math of the rays for indirect lighting…

“Think about this like a maze. With a regular path tracer there are many routes to the exit of the maze, and it can only be solved by starting at one end and finishing at the other, but with a “Bidirectional Pathtracer” (VCM) the maze can be started at both ends and can be solved when the routes meet in the middle.”

So this allows for some more accurate math in the bounce light. With VCM for example caustics aren’t switched on, they’ll just occur naturally. (see more info about caustics)

 

SOME RIS RENDERING TERMS EXPLAINED

Pathtracing: This is the type of renderer RIS is. It traces light paths and includes bouce light. Other pathracers are, Arnold, Hyperion (Disney) and Manuka (Weta)

Grain is the biggest enemy of Pathtracers. And typically they’ll be slower to calculate bounce light than indirect lighting tricks like Mental Rays Final Gather. But the results can be more realistic.

Bidirectional Pathracing: Where the pathtracing is calculated from the light and the camera at the same time. Integrator VCM is bidirectional and Pathtracer is normal one way pathracing.

Converges: in simplest terms the longer the ray tracer render runs – the better the image gets towards the final. Converges guarantees that the render does not introduce persistent artifacts, former technologies did so. Convergence is a vital part of a good path-tracing renderer.

Physically Based Rendering: (PBR) Using real or measured materials and everything is like a real set.

Ray Sorting: In the following video is what the Hyperion renderer (Disney and is not in Renderman) does to speed render calculations by lumping similar rays together for efficiency. Maybe we’ll see a ray sorting Integrator in the future.

The following fantastic video from disney explains pathtracing.

 

INSTALLATION (MACOSX but should be similar for PC)

Create a Username and Password for the renderman forum
https://renderman.pixar.com/forum/
Download
http://renderman.pixar.com/view/get-renderman
Step 1: Register for the RenderMan Forums
http://renderman.pixar.com/view/NCR-Register
Step 2: Download & Installation
This will download a small file 10 mb with an installer.
Run the Installer and use your login.
If you wish to install on 2 versions of maya click “show all to reveal the other installers” Will default to 2016
Will download the installer from the web.
* Regarding running both versions of 2016 and 2015 at the same time
OSX: I had a problem on v19 where the shelf didn’t appear in 2016 when I installed both 2015 and 16 together. So I grabbed the shelf from the prefs folder in 2015/prefs/shelves, copy and pasted that folder into 2016/prefs/shelves and everything was ok.
Windows: There’s been some problems regarding environment setup on Windows with 2 versions of Maya. Hopefully this is a temp problem. More details can be found here…
https://renderman.pixar.com/forum/showthread.php?s=&threadid=27811

 

Initial Setup

Once the shelves have loaded it’s recomended to do these things…

To have the IPR work inside maya and not in the IT program go…
Renderman > IPR (optionbox) > display to “renderview”

To have the rendertimes appear in the IT render widow for proper renders go
Renderman > Render (optionbox) > Display > Show Render Times (check on)

I’ll tend to render proper renders in IT and IPRs inside of Maya.

 

IT Setup

Inside of the IT program (which will automatically open if you render a proper frame not IPR) it’s important to switch on…

Window > Catalog (on)

This will show all your renders and allow you to compare.

I also switch on

Window > Pixel Readout (on)
and exposure settings
Window > Monitor Controls (on)

“r” is the hotkey for rendering a new image, you do not need to bank the old image. (see IT viewer)

To make the IT window always stay on top while clicking other windows
Window > Window Always On Top (or press t)

Wipes in IT
1. click the image in the catalog you want to be the background for the swipe.
2. image > toggle background (it should go red)
3. click the image you want to compare
4. Select the Wipe Tool and click drag over the image, you can compare now.

 

Linear Workflow in v21 and Higher


In v21 Linear workflow is good to go. If you’re using pxrTexture nodes then you’ll need to check on “linear”, regular maya file nodes are good with the default settings.

 

Linear Workflow in v20 and lower


Linear workflow is setup out of the box and will render as .exrs by default. In 2016 in v20 there’s one thing we have to change.

Render Settings (Renderman RIS) > Features > Linearize Colors > Turn Off

This needs to be left to on in 2015 though.

Maya’s swatches need to be set to the drop down…

Mixing Color Space In: “Display Space” for RGB values to enter correctly as per Maya in general.

Renderman Linear Workflow (pretty outdated but interesting)

 

Samples

The main slider you want to wrap your head around is samples. This is the overall quality of the render. The lower the number the more noise you’ll have but fater render times. This is available in both the

Render Settings (shift 5) > Sampling > Max Samples
– (adjust this for limit on Renders)
Render Settings (shift 5) > IPR Sampling > max Samples
– (adjust this for limit on IPR Renders)

 

If Rendering Glass

It may start to render black, if the specular rays aren’t high.
Render Settings (shift 5) > Sampling > Default Ray Depths > Max Specular Depth

You can up this to 4 or higher for glass depending on how many glass surfaces you’re looking through.

 

Setting Up Lights (IBL setup)

Setting Up Renderman RIS is very easy. See this tutorial for some instructions…

 

Pixar Resources

Community Home
Resources
Tutorials

 

Download Pixar Light Setups

Renderman Light Rigs
Renderman IBLs

 

RGB MATTES v21 and Higher


RGB Mattes have changed again in v21. I’ll try to script this at some stage!

This video shows the sort of process but there’s a couple of key changes since the new pxrSurface shaders don’t have AOV slots, instead map to pxrSurface > utilityPattern attribute. This can only be assign in the node editor or hypersahde. It is invisible in the Attribute Editor!

(at 4 mins see the process, see notes for how to make 2nd and third mattes)

To make RGB Mattes

1. ADD AN AOV LAYER/S
a) Renderman > Render Settings > Final > Outputs > Add Channel Outputs > Matte
b) Add a colour Matte ID, you can add multiple each one will be 3 channels, RG and B
c) rightclick on the matte id “Create Output From Channel” for each matte
d) click on the Matte ID Group, and looking in the options > image format > tif 8 this is a good option. No need for 32 bit color.

2. CREATE PXRMATTEID NODE AND LINK IT TO THE SHADER
a) Select the shader and open in the node editor (alt 4)
b) hit tab and type “matte, select the pxrMatteID
c) In the node editor/hypershade expand the pxrSurface up by clicking on the little stack icon nest to the s on the node until it opens largest.
You’ll see the attribute `utilityPattern` at the bottom of the node, open it
d) connect the pxrMatteID > resultAOV attribute to the first pxrSurface > utilityPattern slot, usually 0
d) In the pxrMatteID assign the number channel you wish to assign, ie start from 0

2. ADD ATTRIBUTE TO SHADER “MATTE ID”
a) Select the PxrShader in the attibute editor go Attributes > Renderman > Manage Attributes
b) add matte ID to match ie. 0
c). Find the extra attribute “matteID” (Scroll down in the shader’s extra attributesm it’ll now be added at the bottom)
shader > extra attributes > Matte ID x
d) now added to the shader and enter a colour usually pure R or G or B
*Note remember there are 3 colours rgb per matte ID, so you can have 3 shaders on a single matte ID

5. Render using IT or Batch, won’t work in Maya’s render View
In IT rendermans image tool, you’ll see the triangle icon like a folder, open the image up to see mattes. Or on batch render it will render extra images.

 

RGB MATTES v20 and Lower


This scripted method is easiest

OTHER WAY
Another way of doing mattes is here, I used to teach this but the script is easier…

(at 4 mins see the process, see notes for how to make 2nd and third mattes)
To make RGB Mattes (seems to be some small accuracy issues)

1. CREATE PXRMATTEID NODE AND LINK IT TO THE SHADER
a) Select the shader and open in the node editor (alt 4)
b) hit tab and type “matte, select the pxrMatteID
c) Middle click drag the pxrMatteID into the shader’s “input AOV”
(the attribute must go yellow, so drag onto the b&w icon)
d) In the pxrMatteID assign the number channel you wish to assign, start from 0

2. ADD ATTRIBUTE TO SHADER “MATTE ID”
a) In the Shader go Attributes > Renderman > Manage Attributes
b) add matte ID to match
c). Find the extra attribute “matteID” Scroll down in the shader’s attributes
shader > extra attributes > Matte ID x
d) now added to the shader and enter a colour usually pure R or G or B
*Note remember there are 3 colours rgb per matte ID, so you can have 3 shaders on a single matte ID, matteIDs are assigned to an image in the next step…

3. ADD AN AOV LAYER
a) Renderman Controls (first icon in shelf) > Final > Outputs > Add Channel Outputs > Matte
b) Add a colour Matte ID
*note One Matte ID stands for 3 colours RGB that are assigned in step 2.d, so 3 shaders can be on one Matte ID.
c) rightclick on the matte id “Create Output From Channel”
d) *Note in theory you should only need 8 bit colour for RGB mattes. But I’ll look into that later, there seems to be a way, by selecting the Matte ID Group, and looking in the options > image format > tif 8 for example.

4. Check IT AOVs are visable
AOV are the extra images such as mattes and extra passes a renderer renders out, we need to be able to see the AOV images in It, this should be ok and on by default.
You can see AOVs by going (these should be on by default)
Render man > Render (options) > Display Options > Show AOV’s on and Split Multichannel AOV’s on

5. Render using IT or Batch
You will see the triangle icon like a folder, open the image up to see mattes.

 

Denoise

Denoise is a batch render effect that will place two images in your, one sceneName.exr the other sceneName_filtered.exr

projectDirectory/renderman/(scene name)/

*Denoiser is not supported in IT or in the render view in v20, it must be batch rendered. This might not always be the case as it’s in an early incarnation.

1. Open up the render settings
2. Go to Sampling > Denoise > Set to “Frame”
Or for animation set to “Cross Frame*”.
3. Batch render

*Cross Frame will potentialy fail on farms where many computers are rendering.

The image will need enough samples to render correctly, otherwise the filtered image will appear blotchy.

There will be two images rendered from each frame, the denoised image will have _filtered in the filename, here’s the results of croc frame one…

crocImage.0001.exr (28.5 mb 16 bit at 540p)
crocImage_filtered.0001 (2.9 mb 16 bit at 540p)

The regular image is very large in filesize as it contains lots of extra .exr layers embeded to help the filtering process. You should delete these files quickly as they will fill hard drive space easily.

The denoiser works great and it’s best to have it on most of the time. The downsides of the denoiser are for things like fur which can loose details. Also high contrast blown out areas, like the rim light of this croc or the window in the bottom image which will alias badly. Otherwise it works well. Croc was rendered at just 32 samples and rendered in 47 sec at 540p resolution.


crocImage.0001.exr Straight Render (32 Max Samples)
 

crocImage_filtered.0001 Denoised (32 Max Samples) Note the aliasing around the rim like areas.
 

 

Depth Of Field

DOF is super easy, use the inbuilt maya depth of field setting on the camera.
select camera (k) > attribute editor > depth of field > Depth of Field On > Focus Distance
Change The Distance in cms to how far things are from camera, if unsure you can use.
create > measure tools > distance tool
You can rig this up to keep objects in focus with moving cams etc.
The amount of blur is F Stop, a camera an fstop of 22 is mostly everything clearly in focus. Lower values like 1 will have a lot of blur.
Focus region scale is like a multiplier, 1 is default, bigger numbers will be clearer with more area in cms in focus.
If your scene is heavy you can Mute the GI Light depending on the speed of your machine. *Not sure where this is yet.

To attach controls for controlling the Bokeh, which is the look of the blur, round lens effects/multisided artifacting in the blur select the Main Camera and attach
Attributes > RenderMan > Aperture Controls.

DOF can speed up render times in REYES not sure about RIS though, the settings are missing in the RIS UI.

 

Rendering Half Float In RIS


In Renderman it’s also super confusing to change the 16 bit setting. Default is 32bit. That’s done with
First Icon in the shelf > Final > Outputs > RGBA > Add remove Settings > Open Exr Pixel Type > rightclick add. > change from float to half.

Then you might as well add exr compression too.
same as above > Add remove Settings > OpenExr Compression > plz

 

Rendering Motion Blur In RIS


Rendering Mo Blur in RIS is pretty easy and relatively fast. Though it’s faster to render 2d blur in the compositing package the RIS moblur will look better.

Main settings are
Render Settings > Features (Tab) > Motion Blur
Check on
– Motion Blur
and
– Camera Blur
Then play with
– Shutter Angle (how much blur)
– Motion Samples (quality)

One obscure setting is needed for camera blur go
1. Select the render camera
2. Windows > General Editors > Attribute Spread Sheet > Render Tab > Motion Blur On!

Otherwise camera blur will not function

 

Globally Controlling Exposure

Globally control exposure without affecting the image 0 exposure level is found in
Render Settings > Passes > Outputs > Exposure (first value as the second value is gamma)
This only works in IT and batch renders not inside of Maya IPR render view.

 

Physical Camera

Physical Camera is in the Render Settings and can control a bunch of things associated to the camera like fish eye distortion, shutter speed, vignetting, chromatic abberation. Really easy to use in combo with IPR renders.

Render Settings > Features > Camera Type > Type > Physical Camera

Then adjust…

Tilt Shift Seems to move the camera up down left right?
Lense Distortion is for the cool fish eye effects, have fun!
Chromatic Aberration is an artifact in real camera lenses that seperated the rgb values, this is a pretty subtle effect usually but can help to match real world lenses.
Vignetting
Natural will give a natural vignette effect (recommended though it’s very easy to do in post and will look good and full control)
Optical is a more fancy vignette and will introduce noise so usually avoid.
Shutter is for motion blur effects.

 

Opacity Settings

Opacity/Transparency settings are a little strange in RIS, see this page for more…

Renderman Docs, Opacity and Transparency and Translucency

 

Easy Quick Fur Settings Renderman

1. Setup Maya Fur
Switch on Maya Fur Plugins
Rendering > Fur > Attach Fur Description > Fur (or use GMH for hair)
Must be in old legacy viewport to see fur
Attribute Editor > UV samples to 128 say to help grooming
Fur Description Is The Fur Curve Settings
Baldness is for texture map for fur

2. Renderman Shader Hookup
Load Renderman
In the hypershape create a node PxrMarschnerHair
Add Custom Attribute (attr Editor) to X_FurFeedbackShape
Go to Extra Attributes then rightclick on Custom Shading Group Attributes then PxrMarschnerHair1SG node just created

3. Maya Tweaks
For the fur settings you can use maya presets, Renderman uses the native maya settings for anything to do with the curves etc

4. Shader Tweaks
Renderman shader PxrMarschnerHair1 will be for colour and spec, eg material shaders.
Rendering Fur Example

 

Fur Setup and Mapping Colour to Hair and Fur

The following videos show how to use fur in Maya and Renderman. Mapping Colour to the fur is odd. The colour part starts at 9:10mins, the rest covers the full fur setup including some Maya setup and grooming.

These videos are from the bitsized tutorial section by Mark Flanagan see that here

Grooming Maya Fur With XGen (not Renderman just Maya Grooming tips)

 

Rendering Hair Example

*Note this video uses the old fur shader. Try the PxrMarschnerHair shader instead.

 

Fixes For Black Eyes Errors Caused By Lens Shaders

This is regarding the glass shader on eye lenses.
“Disable auto bias on the eyes and set the trace bias (still on the eyes) very low.”

 

Renderman Talk Notes Pete Moxy Sydney 10th June 2015

Notes regarding new versions and future of RM and RIS.

Talk last night turned out to be pretty good, a fair bit longer than the talk at UTS so we were told. Lots of good info regarding the future of renderman, my money is backing renderman since we are only on version 1 of RIS and already it’s quite decent, they are also very focused on getting render times down and two things were mentioned regarding render times…
-Light localisation in new version should decrease interior render times significantly, nice! Will be in a new version (maybe v21)
-Disney Denoiser is coming in v20, which is 4 -6 weeks away, that should be a life saver!! And looks very cool. The denoiser produces very large exr files, because it renders extra passes with the noise info, then it uses that to remove the noise in the beauty layer, this isn’t like a regular nuke or AE denoiser. It’s much more powerful. And looks very nice. smile emoticon
Other Notes
Main notes from last night were…
– RIS is def the future of renderman, not worth learning much of REYES

-v21 is due late this year, will have more integrators, which are like variations of the renderer, one will focus on creating great volumes like coloured water and wax.
– Production hair coming for RIS based off Finding Dory Tech.
– See the facebook group “Renderman World” for community facebook group dedicated to rendering in Renderman
– Day and Night pack looks good, it’s like physical sun and sky I’ll try and download and figure it
– There’s a preset pack of RIS shader presets that can be bought for $100…
http://lollipopshaders.myshopify.com/products/ris100
– GPU was demo’d though not any mention of it making it into the new versions. GPU is great for artists at home, but it’s not so cost effective in production since GPUs run very hot and power costs are the biggest cost now for render farms, cooling etc. Pixar is more focused on CPU cloud based rendering and distributed rendering so you can use many cloud computers to render frames simultaneously. That’s where the future lies they think not in the GPU. I’ll be interested in this since it may not be so good for students at home. GPU stuff does look incredible. Octane is a good example of that.
– You can render an entire sequence at low samples like 64, then continue rendering after checking the frames without needing to rerender… or throw the sequence and not waste time.
– Pixar is having problems with render farms regarding licensing, particularly with google and should be able to sort it. Hopefully soon
– Ed Catmull is very behind Renderman and increasing resources in that dept. Team is growing and they are throwing a lot of money at it.

Instructor

Andrew Silke

Last Updated

Nov 2016

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