Animation (prepass) / (rendering) with V-Ray

If you want to use V-Ray Animation (prepass) / Animation (rendering) mode, you must select the « Mode Animation Prepass / Rendering » option in RANCHecker.

We recommend you use this mode for all your animations which use irradiance map in your GI solution as a way to eliminate flickering and improve fluidity.

That kind of animation project can be done in one or two steps, that is one or two RANCH projects. Each method has its own advantages.

Method 1 (standard): Prepass and Rendering in one project.

This method is the simplest. When you choose it, RANCHecker will create the two scenes (one for the prepass and one for the rendering) and includes them in the .vu3 project. The two scenes will have the same number of frames and will be rendered at the same definition.

When the project is processed on the Ranch, the prepass will be computed first and then the rendering phase will use the previously computed .vrmap files. At the end, the project ftp directory will contain both the .vrmap files and the final images.

To select this method, just choose the “Mode Animation Prepass / Rendering / Auto (recommended)” option in RANCHecker VRay Options.

Mode Auto

This Auto mode contains 2 sub-options:

  • Override Interp. Frames’ allows you to easily change the ‘Interp.frames’ value which will be used for the Rendering phase.
  • Lower Interp. Samples for final render’ allows you to reduce the ‘Interp samples’ value for the Rendering phase. Larger values tend to blur the detail in GI although the result will be smoother. Smaller values produce results with more detail and reduce the render time, but may produce blotchiness if low Subdivs are used (see picture below). More info can be found here.

To set this value during your rendering tests, we advise you to start using a low value, increasing it step by step until you reach the expected result. If for some reason you cannot undergo some tests, you can use the ‘Apply Ranch formula’ button, which automatically calculates and applies the minimum recommended value.


During the render on the RANCH, the first 50% of progress displayed in the RANCH Waiting List will correspond to the Prepass phase, and 51 to 100 % will correspond to the Rendering phase.

Method 2 (advanced): Prepass and Rendering in two projects

Although a bit less simple than the first method, this one may be useful in some cases. For instance, you can render all the .vrmap of a long sequence in one project, and then reuse them for several following projects without having to recompute the GI each time. And if you have to render the same animation several times with modifications to the scene that do not affect the GI (color changes for some objects for instance), you will save time by reusing the previously computed .vrmap.

  • The first project is used to compute all the .vrmap files (one for each frame).
  • The second project does the actual rendering. Each rendered frame uses as its Irradiance map an interpolation between the previously rendered .vrmap files.

First project: Irradiance maps generation (Animation Prepass)

You have to:

  1. check the 'Mode Animation Prepass / Rendering / Manual' option
  2. check the 'Render vrmaps (step 1)' option.

When RANCHecker prepares the scene, it automatically changes the name of the Irradiance map files to be the same as the output bitmap files (which won't be generated by this first project anyway) e.g. if the output bitmap is 'MyProject.png', the vrmaps will be named 'MyProject.vrmap'. Do not change this name when RANCHecker has finished its work.

For the prepass phase, RANCHecker will redirect the .vrmap output path to the standard RANCH output path which is C:\3dsmax\Output.

Second project: images generation (Animation Rendering)

Make sure you didn't change the output bitmap and/or the Irradiance map names between the first project (prepass) and the second one (rendering). The names must be identical for the second project to find the .vrmap files created by the first project.

You have to:

  1. check the 'Mode Animation Prepass / Rendering / Manual' option
  2. check the ‘Final Render using vrmaps (step 2)' option
  3. check the 'Project ID' square and enter the vrmaps project ID.

Mode Manual

With this ID number (for instance '65432'), the RANCH will find the .vrmap files of the first project and use them for the rendering pass: it saves you the hassle to download first the .vrmap files and then reupload them in the second project. It also means that you must send the second project at most 5 days after the first one, that is before the ftp directory of the first project is automatically deleted.

For the Animation (rendering) mode, do not forget to configure the Interpolation frames value. The default value set to 2 works for most of the animation. Nonetheless, we advise you to start testing with a value set to 1 which could be enough and lower the render time. Also, you might need to increase the value to 3 (rarely more) for complex scenes.


3dsmax/pre-pass-rendering.txt · Last modified: 2018/01/09 14:22 by ranchadmin