In my current project, when I hit render, Phoenix calculates self-illumination from the grid and when it’s done, it calculates it again. Should this happen?
I’m using quite high light resolution (30% in 300 million grid), so it takes about 3 to 5 minutes per pass.
phoenixFD_adv_30301_max2016_vray_30_x64_27443
Hey,
If you have just one grid, could it be that it calculates 2 passes for the additional lights and another one for the self-illumination?
Cheers!
Well, it’s hard to say, because those windows flashes so fast.
But it looks like it’s first calculating self-illumination and the additional lights pass 1 and 2. After that, both self-illumination and additional light passes are calculated again.
Hmmmm, only thing I can think of would be two simulators, or alternatively - two Phoenix atmospheres. If these are okay, would it be possible to share a scene with this issue?
One great thing I learned from this.
I’m now rendering the whole thing using Ray-traced Self-shadowing and Ray-traced scattering without light cache and it looks damn good. …and the rendering speed is almost the same or faster!
This is a very special case, usually it’s tens of times slower 
Hey, just an update on the issue - the reason was the Grid Tex that was plugged in as RGB color. First off, it shouldn’t have been accounted for at all, since it was disabled. The second problem was the texture triggered the simulator to prepare for rendering, which included calculating its self-illumination, and the results were not cached for the moment when the simulator itself started preparing for rendering. The fix will be in Tuesday’s nightly build. You could workaround it for now by disconnecting the grid tex completely from the Smoke Color slot. Thanks very much for catching this!