This page introduces and provides information on setting up Distributed Rendering.

 

Overview


Distributed rendering is a technique for distributing a single render job within a single frame across many computers in a network. There are different approaches to doing this, but the main concept is to reduce the render times by dividing different parts of the rendering pipeline and giving each participant different parts of the job. 

To use the distributed rendering feature you need to have both V-Ray for 3ds Max and Autodesk 3ds Max installed on the Render Client when rendering with V-Ray Next. When using the V-Ray GPU render engine, V-Ray GPU render server installation is sufficient on each server machine.


Organization


V-Ray divides the frame into regions and spreads them across the participants in the distributed rendering. This is done completely through TCP/IP protocol which is the standard protocol of the Internet and thus the most common protocol that is supported by the hardware. V-Ray itself does not need additional file or directory sharing (note that you may actually need some file/directory sharing for the bitmaps or other additional files used during rendering). The distribution management is divided into  Render Clients and  Render Servers.

Render Clients

The render client is the computer from which the rendering is started. It divides the frame into rendering regions and spreads it across the Render Servers. It distributes data to the render servers for processing and collects the results.

Every render client requires a render node license. To see how to set up your render license, see the Set Up Your V-Ray License.


Render Servers

A render server is one of the computers in the network that does the rendering work. A render server requests render data from the render client, processes it, and sends the result back. In any DR job, there can be many render servers.

If any of the servers fails, you should get a notification and the render client will try to reassign the buckets to another server.

 Distributed Rendering is performed differently depending on the V-Ray renderer. V-Ray Next requires vrayspawner to be run on the render server machine, while V-Ray GPU requires V-Ray GPU Render Server or V-Ray Standalone (with server command). 


Step by Step V-Ray Next DR Setup


1. Set up the Render Servers by starting V-Ray Spawner on each server machine. It will start the 3dsmax.exe in server mode which will appear as 3ds Max minimized down in the taskbar. It should have the title "vraydummy.max". (This step is not required if the server machine uses spawner as service)

2. Set up the Render Client. In the V-Ray for 3ds Max interface, enable Distributed rendering from the Settings tab under the System rollout. Use the Render Server button to add the IPs of all your Render Servers.

 

Step by Step V-Ray GPU DR Setup


V-Ray GPU can run on one or more CUDA enabled graphics cards. The GPU devices must be selected before initiating the distributed rendering on each server machine. To specify which cards to use, go to Windows Start > Programs > Chaos Group > Select devices for V-Ray GPU rendering of each render slave machine and pick.

By default, the render slave machine will use all its graphic cards in CUDA DR rendering, if nothing was specified beforehand.

1. Set up the Render Servers. You can do this in two different ways: (This step is not required if the server machine uses V-Ray server as service)

a. Start the render server on each server machine from Start menu > Programs > Chaos Group > Launch V-Ray GPU Render Server for 3ds Max ####

b. Start the V-Ray Standalone and enter the "vray -server" command in the command prompt.

2. Set up the Render Client. In the V-Ray for 3ds Max interface, bring forth the Render Settings and in the Performance tab under the Distributed Rendering rollout switch On. Use the Render Server button to add the IPs of all your Render Servers.

 

TCP/IP Port Numbers


Distributed rendering works over TCP/IP and requires the following ports:

 

Renderer typePort numberPort type
V-Ray Next20204TCP/IP
V-Ray GPU20206TCP/IP

Port 20205 is only used by render servers to broadcast a message that they are ready to join an ongoing DR rendering.

V-Ray Standalone when set as render server receives rendering requests on port 20207 by default.

V-Ray DR Spawner command line options


You can add command line options to the VRaySpawner.

Numa options

You can specify Numa command line options to VRaySpawner.exe to better utilize processor nodes with Numa architecture:

CommandDescription
-numa[=N]Select the number of slave processes to start. If N is not given, N=0 or N>=M, one process per NUMA node will be created. Here "M" is the number of selected nodes using "-node", or the number of all available NUMA nodes if no "-node" is used.
-node=node1[,node2][,node3]...Select NUMA nodes that will be used for the slave process(es). Default - use all available NUMA nodes.
-port=port1[,port2][,port3]...Select listening ports for the slave process(es). If the number of processes is greater than the number of ports given, the last port is auto incremented. The default listening port is 20204 for 3ds max. The render client should be set to use the corresponding port range.
-ServiceRegister vrayspawner as a Windows service.
-UnregServerUnregister vrayspawner as a Windows service.
-cmdparams="<parameters_string>"Specifies a string to be provided directly as an argument to the spawned application.
-tempdir="<temp_folder_path>"Override path for vrayspawner's temporary files folder. Vrayspawner is using %temp% to write some files needed for spawning applications.
-AppName="<excutable_file>"Override spawned application file name. For example, for 3ds Max the default name is 3dsmax.exe.

 

 

Example: Using 3ds max #### and a system with 8 NUMA nodes:

vrayspawner####.exe -numa

spawns eight 3dsmax.exe processes, every running on single NUMA node and using listening ports 20204-20211

vrayspawner####.exe -numa=4

spawns four 3dsmax.exe processes, every running on two NUMA nodes and using listening ports 20204-20207

vrayspawner2012.exe -node=3,5,6 -ports=30000,40000

spawns three 3dsmax.exe processes, running on NUMA nodes 3,5 & 6 and using listening ports 30000, 40000 & 40001

vrayspawner2012.exe -node=2,3,4,5,6 -numa=3

spawns three 3dsmax.exe processes, running on nodes (2,3) (4,5) & (6) and using listening ports 20204,20205 & 20206

 

#### is the 3ds Max version.

Notes


  • Every render server must have all the plugins and texture maps in their proper directories loaded so that the scene you are sending will not cause them to abort. For example having a PHOENIX plugin used in the scene will cause a server failure in any of the servers that do not have the PHOENIX plugin installed. If you have mapped your object with a file named JUNGLEMAP.JPG and you do not have that map in the BITMAPS directories of the render server installation - you will get bucket rendered at that machine as if the map was turned off, unless you also turned on the  Check for missing files  option in the V-Ray System rollout, in which case the render server will refuse to render the scene.
  • When you cancel a DR rendering, it may take some time for the render servers to finish working and they may not be immediately available for another render. 
  • Default lights are not supported in DR mode and will not render. If you need any lighting in the scene, you should add it explicitly.
  • The default system temp folder, usually C:\Users\<username>\AppData\Local\Temp on Windows (%TEMP%), is used for copying the assets if the VRAY_ASSETS_CACHE_PATH environment variable is not set.
  • V-Ray DR can be run automatically as a Windows service whenever the machine boots up. For more information, see Set Up V-Ray Render Service
  • If you see a 3ds Max window flashing on the taskbar and then disappearing, right-click on the V-Ray DR spawner icon in the taskbar tray, select Exit to close the DR spawner, and try running a regular Backburner job with this machine as the server. After that, try to start the V-Ray DR spawner again.