How To: Render V-Ray Irradiance Maps, Light Caches, and Photon Maps on the ResPower Super/Farm™

NEW! CHANGED PROCEDURE!

On September 17,2006 ResPower introduced irradiance and light cache map caching. This new feature allows each render node to download a copy of the irradiance map to each computer in order to avoid network utilisation for the irradiance map at render time. This has shown in testing to provide significant speed increases. Read below for details on setting up your scenes to use this new method.

The gist of the new method is that the Virtual Y: drive is no longer necessary for the irradiance map or light cache. Instead of placing your irradiance maps on the Y: drive, generate and link them in the C:\ResPower\temp folder. Next, upload them next to your .max file, and in the Render Wizard, select the irradiance map when you submit your job.

Overview

Bad V-Ray Map Setting: This is a bad path for configuring your V-Ray lighting map. V-Ray will not find your map, and your renders will turn out dark. Maps must be in the location C:\respower\temp\

Good V-Ray Map Setting: This is a good path for configuring your V-Ray lighting map. It points to C:\respower\temp\ where any files cached through the Render Wizard are placed.

The ResPower Super/Farm™ proudly supports 3dStudio Max rendering using the "V-Ray" render engine. This tutorial discusses how to use the ResPower Super/Farm™ to render .max files using V-Ray irradiance maps, light caches, or photon maps, in all supported 3dsmax versions. This tutorial was written using V-Ray 1.47.03 but the concepts should be similar for any version of V-Ray.

This tutorial can be viewed as a modification to the main 3dsmax tutorial. There are several new steps for you to take:

• Generate an irradiance map (*.vrmap) on your machine.
• Upload your irradiance map with your scene.
• Generate and upload a light cache (*.vrlmap).
• Generate and upload a photon map (*.vrpmap).

For Split/Frame users, you can generate your maps at a lower resolution than the final render will be and use those maps on the Super/Farm. this will greatly accelerate the Super/Farm's ability to render your scene.

The Super/Farm unfortunately cannot produce these maps on the "server side," so if you intend to use them, you must generate them on your side first.

When you link your V-Ray maps into your .max scene file, they must be linked to the location C:\respower\temp\. Some versions of V-Ray will fail silently and produce dark frames if the V-Ray maps cannot be found. Newer versions will produce and error and your frames will die.

Generate an irradiance map (*.vrmap)

Configure V-Ray to Render: These are the settings you should use to generate an irradiance map.

Configure 3dsmax and V-Ray - Configure 3dsmax to render every nth frame in the range you intend to render at ResPower. For example, if you intend to render frames 0 - 1200, you might configure V-Ray to render every 120th frame, so that the irradiance map has 10 increments. Alternatively, you could choose every 100th frame so that the irradiance map has 12 increments.

On the Renderer tab, go to VRay:: Irradiance map -> Mode, and select "Multiframe incremental". Go to VRay:: Irradiance map -> On render end, and turn on "Don't delete," "Auto save:", and "Switch to saved map." Choose the "Browse" button to provide a file name to save to. Be sure that the file name you select is in the folder C:\respower\temp. For example, a good V-Ray map filename looks like this:

Click the Render button. Vray will render the frames you chose above and generate an irradiance map as a by-product.

Set the frame-step setting back to one. If you fail to do this, 3dsmax will not render the correct frames on the Super/Farm™, and will instead render every nth frame n times. For example, if you choose every 10th frame, the Super/Farm will render every 10th frame, but 10 times each, and your output folder will contain only every 10th frame.

Save your scene - This probably seems obvious, but you must save the changes to your scene file prior to uploading it for the render to reflect your design. We recommend always appending a version number, and increasing that number with each save, e.g., MySceneV01.max, MySceneV02.max, etc.

Upload Your Irradiance Map With Your Scene

Using the Super/Cache option on the Render Wizard To use a V-Ray map on the farm, simply upload the map alongside the .max file that uses it.

When you submit your job with the Render Wizard, a section labeled Super/Cache will give you a list of all files available for you to cache. Simply select the V-Ray maps you want to use, and click the arrow pointing to the right to move them into the list of files to cache. Any files in this "files to cache" list are copied into the C:\respower\temp folder on each render node at the beginning of a job. This way, when your scene tries to load a V-Ray map from C:\respower\temp, the file will be there.

A big advantage to caching the files is that the render engine does not need to pull it across the network at render time. This can result in a significant performance boost for your renders on the farm.

Generate and upload a Light Cache (*.vrlmap)

This is essentially the same process as for an irradiance map, only you work with the settings in the Light Cache rollout instead of the Irradiance Map rollout.

Generate and upload a Photon Map (*.vrpmap)

This is essentially the same process as for an irradiance map, only you work with the settings in the Photon Map rollout instead of the Irradiance Map rollout.