How to render Phoenix fire without fireflies?

[LudvikKoutny]

Hi,

I am doing a job where I have to render an interior on fire. This means that the Phoenix sims will have to be main sources of lights and reflections. Is there any way to actually render that in Vray 3.6 in a reasonable time? When I render, I get very rough fireflies that will never clean up. I've searched the forum, but I've only found the posts about how it is a limitation. I am curious how do the people use this in production then? Basically, I just need to get my job done, but I have no idea how. The I tried to render one image completely clean, but it was about 30 hours on modern dual xeon machine. And I will need to be rendering an animation of about 1360 frames.

Thanks in advance.

[georgi.zhekov]

Hello,

Unfortunately as you have found out there are some limitations when rendering fire and there are reflective objects in the scene. We're aware of the problem and it's in our to do list for things to improve.
For now what you can do is to turn off the light emission (or lower the Light Power on Scene to a really low value like a 0.001) from the Phoenix options and create some invisible lights where the fire is. This won't produce the exact same result but should render a lot cleaner.

[LudvikKoutny]

Hello,

Unfortunately as you have found out there are some limitations when rendering fire and there are reflective objects in the scene. We're aware of the problem and it's in our to do list for things to improve.
For now what you can do is to turn off the light emission (or lower the Light Power on Scene to a really low value like a 0.001) from the Phoenix options and create some invisible lights where the fire is. This won't produce the exact same result but should render a lot cleaner.

Hi,

actually the light emission is clean. It appears to be the glossy reflection of the Phoenix grid what is causing extreme fireflies. If I turn off light emission I get rid of the smooth clean lighting and the scene is distilled down just to those firefies. I can not really make Phoenix grid invisible to reflection because it has no such switch in Vray object properties, and it ignores the visible to reflection/refraction switch in 3ds Max's native object properties.

[LudvikKoutny]

Ok, so I've randomly found a combination of properties which makes it work. I have no idea why it works, but it does, so I'll take it:

[georgi.zhekov]

Can you send us a the scene so we can take a look? If it's a large one you can send it to support@chaosgroup.com. For the Fire just a single cache file will do.

Thank you,

[LudvikKoutny]

Can you send us a the scene so we can take a look? If it's a large one you can send it to support@chaosgroup.com. For the Fire just a single cache file will do.

Thank you,

I'll try. Need to ask for permission first.

[jeffbrown]

Just wanted to thank Ludvik for posting his solution -- I was having the same issue. Disabling those 2 VRay properties solved my "fireflies". Thanks!