Rendering Phoenix Fire Sim

[carn723]

I seem to be a little lost on settings to use for a decent speed render using Phoenix out of Vray on 3d studio max. I was hoping to get some assistance as I am not that advanced in Vray and every time I try to render out a scene with the fire in it I am getting like 3 hours a frame, and that is at the start of the fire when it only shows in a small area so I can only imagine once the fire gets bigger and fills more frame.

Is there some kind of optimized settings for Vray to use when rendering fire to get decent results for a video?

Thanks for the help
Anthony

[LarsSonparsson]

Could you give some details of your render settings?
Are you rendering with gi? With motion blur? How big is the grid?

Anyway it shouldn't take that long. Sample scene could help also.

[carn723]

Here is the scene.

I do have GI enabled and am using a light kit from A&G Tool Co. that basicly puts texture maps with lights in scene for reflections of soft boxes and such. I only have 2 lights total in scene. I find the frames without the fire introduced to be about 25 min a frame if I remember correctly but the end of the sequence where the fire is introduced is when frames went into the hours. My last frame took 5 hours and total time to render 81 frames was 47 hours.

I do have motion blur enabled through the vray camera so not sure if that is killing things but figured it wasnt on the earlier frames without the fire. I have been told vray is much more efficient with motion blur in vray camera then max is but if need be I suppose I could do motion blur in post.

I am rendering 1280x720, Adaptive Subdivision - Min 0 Max 2 - Clr Thresh .05, GI Primary bounces Irradiance map - Medium animation preset, Secondary bounces Brute force.

Here is the video that I got from rendering 81 frames. Not the best quality but my experience with rendering is limited. I am affraid to increase the quality of anything for better results worried about what it would take to render the fire.

I have even tried changing things to adaptive DMC and adjusting settings all over the place and all I end up with is a real noisy image that still hangs a long long time on fire.

Appreciate any suggestions and sorry if I am not giving correct info when it comes to render settings.
Anthony

[Ivaylo Katev]

the GI+smoke combination renders much slower, and i would recommend to render the smoke in separate pass without GI, except the cases when you really need GI for some reason.
i have talked with people who create smoke and fire production, and they were quite clear: it's much better to invest the machine resources in grid resolution and motion blur, than to calculate GI.

[carn723]

Thanks for the tip I will try that. So I should render background and fire with GI in one pass and then smoke on its own pass without GI correct? Is there a easy way to disable the smoke for render and enable only smoke for other render? Also is there anything special I have to do when rendering smoke as its own pass to get it to integrate correctly when compositing?

Thanks for the help
Anthony

[Ivaylo Katev]

you can disable the smoke from the smoke color panel
about the fire lightning with GI you can see the fireplace scene that comes with the installation (...documents\phoenix fd\samples)

[carn723]

Once I disabled the smoke that brought the render back to normal times. I only have the chocolate and submarine sample files so couldnt check out the fireplace scene but is there something I am supposed to change for the GI with the fire or since it is not the only item lighting the scene can I leave it at whatever is default?

Thanks for the help
Anthony

[Ivaylo Katev]

strange that the fireplace scene is not installed!
anyway, here is it

[carn723]

Thanks for the sample scene.

[carn723]

ok I have reached the point where I am rendering just the smoke now. I am a little lost on how to do that. Do I go into the fire tab for colors and transparency and disable the fire but leave the smoke or do I still need the fire to emit some light for the smoke to look correct? What do I do with the rest of the objects in the scene just hide them so I get only smoke or do I have to do something else so they still interact with smoke but dont show up in render?

Thanks again

[Ivaylo Katev]

you need the fire, the turn the rest of the objects to be mate objects (vray properties)