Part 1: Network and User Setup |
Part 2: V-Ray Installation |
Part 3: Distributed Rendering |
Part 4: Backburner
Tutorial by Morné Erasmus
Part 3 - Distributed Rendering
Congratulations you have finished setting up all the IT Stuff. We are now just about ready to render. Open a completed V-Ray scene where you have already added lights, cameras and applied textures. Press "F10" to open the "Render Setup" window. On the tabs on top click on the "Settings" tab. Scroll down a bit and under the "V-Ray:: System" rollout, you will find a section for Distributed Rendering. Tick "Distributed rendering" and click on "Settings…" next to it. Here add all your slaves one at a time by clicking "Add server". Click "OK" when you are done.
Image 14: DR settings.
You don't need to add "MainPC1" as a render slave, as it will automatically render with DR. Now you can click "Render".
HUH?! What is going on? You did everything right so far but the slaves seem to render without texturing your scene. What's up?
Image 15: Problematic render result due to incorrect file paths for textures.
There could be various reasons for the problem you see here. The most obvious is that you didn't use UNC paths when you added your textures when making materials. Distributed Rendering does not like mapped network drives. So in 3ds Max go to "Asset Tracking". As you get to "Asset Tracking" differently depending on which version of Max you're running, please refer to Max help on how to find it. In "Asset Tracking" you can see the paths of all your bitmaps used in the scene. Currently you have something like "C:\Textures\TimberFloor.jpg". To resolve this you can just make a "Textures" folder on each render slave and copy the "TimberFloor.jpg" file into it. For obvious reasons this is not the way to do it and you will be copying till you're blue in the face. The other alternative is that you have a mapped network drive and the texture for the floor is referenced as "Z:\Textures\TimberFloor.jpg". Again this is not UNC and V-Ray won't like it. The correct way to use UNC paths is like so: "\\MainPC1\Textures\TimberFloor.jpg". In "Asset Tracking" right-click on the wrong bitmap path then from the menu that comes up select "Set Path" and set the correct UNC network path.
Image 16: Correcting the file paths in Asset Tracking.
Ok now hit "Render" and see your result:
Image 17: Better, but still problematic. What happened to the lights?
Hey all the textures are definitely rendering but now something else weird is going on. Some areas render darker than others! Noooooo! Again there could be various reasons you're getting these results, but again the most obvious reason is paths. When using lights that reference an external IES file (a physically correct file supplied by lighting manufacturers) you also need to make sure that the IES file you reference uses UNC paths for example: "\\MainPC1\Lights\IES\123456GE.ies". Go ahead and set the correct path for all your IES referenced files in "Asset Tracking". Ok now hit render and see your result:
Image 18: Correct DR rendering!
Perfect! Congratulations you have just completed your 1st DR render. When you start getting a bit more advanced you may want to pre-calculate your GI to save time etc. We won't go into the actual technique of how to do it, but you might render with a result like this:
Image 19: Bad render because of incorrect .vrmap paths.
It is not as bad as image17, but you can definitely see some areas render darker again. So what's up this time? All computers can definitely see the textures and the ies files, but then why does it not render correctly? The most obvious answer once again is paths. When you pre-calculated the GI and/or then referenced the file with the render, you used a path like "Z:\Work\ProjectTest\IRMap.vrmap". Change the path to UNC "\\MainPC1\Work\ProjectTest\IRMap.vrmap" and it will render correctly.
If you've done all these steps but you still having problems then the most logical answer is permissions. Somewhere along the line you didn't give the users correct permissions to access the shared folders. You can check this by going onto one of the slave computers that is giving problems and using Explorer try and navigate to the UNC path for example "\\MainPC1\Textures\TimberFloor.jpg". If you can't get there make sure the computer is connected to the network and have the correct share permissions. Sometimes when starting up in the morning, your router may for whatever reason not assign an IP address to one of the computers - this is very rare but does happen. That computer then assigns it's own address usually not in the same range as the other computers. This makes it unable to see the other computers. Just restart that computer and it should be fine. Make sure all computers are logged in with the correct user: "MainDude" for "MainPC1" and "SlaveUser" for "Slave1", "Slave2" etc.
Note on logins - You can automatically login a user during boot, and there are various tools that will help you achieve this. You can also tell the DR and Backburner services to always use the permissions of a certain user, no matter who logged into the computer. Both these techniques are however beyond the scope of this tutorial.
Continue to Part 4 - Backburner
