Blending Irradiance Maps in V-Ray 1.50 for 3ds Max/VIZ

Many of you out there have probably run into the problem of needing motion in a GI lit scene. Usually this results in splotchiness and noise that swims around. V-Ray 1.50 has come up with a solution to address this. You can pre-calculate, and blend your irradiance maps together with the following steps.

First, make an animation with motion in it. I've made a simple reactor simulation for this scene. Here are the steps for creating that:

1. Make a few elongated boxes and animate them moving over several frames. Make a few spheres and position them above the boxes.

2. Go to the Create tab, choose helpers, and switch to reactor. Create a rigid body collection (RBCollection) and place it in the scene. Add all the spheres and boxes you created to the collection.

3. Go to the Utilities tab and click reactor. You can adjust the physical properties for each of the rigid bodies by selecting any of them and scrolling down to the properties section of the reactor utility. (Mass, friction and elasticity).

4. Preview the simulation and adjust it until you are happy, then click Create Animation. It will make keyframes for your simulation.

5. Now you are ready to pre-calculate the irradiance maps:

A.- Switch the renderer to Vray and open the Indirect Illumination tab. Make sure the primary bounce is set to Irradiance map. Go to the Irradiance map settings and change the Mode to Animation (prepass). It's going to generate a sequence of individual irradiance maps.     B.-Specify a location to save the sequence to, and click render. (You can submit this as a backburner job with multiple machines crunching it) Optionally, you can precalculate a Light Cache before you run the IRmap pass to save some time.

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C.-Once the prepass is complete, switch the mode to Animation (render) and pick the first irmap from your saved sequence.       D.-You'll notice that the "Interp. frames" under basic parameters has been ungreyed. The number of interp frames is the number of irradiance maps before and after the current frame that get blended into each rendered frame. They are blended together much like a motion blur pass.

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6. Click render and marvel at the noise-less motion!

Demo Video (640x480) 1.1 MB - Flash Video Click to watch (Opens new window)