We are having problems getting a proper alpha channel out of Octane for our fire Sims. We have 3 logs and a campfire simulation with flickering flames and smoke. We can not figure out how to get the following:
-Logs to properly holdout the flames by being black in the alpha
-Fire to properly render... it appears to be multiplied by the logs, so it is super bright when in front of the log geometry, but falls of to barely there when on it's own.
Please help:)
TFD Holdout Objects and propper alpha channel for fire
Moderator: juanjgon
- rustyippolito
- Posts: 96
- Joined: Wed Mar 08, 2017 10:07 pm
Yes, the absorption value increase definitely helped. I feel like i have to tweak the TFD simulation values because Octane is extremely sensitive to tweaks in the absorption settings. Will keep trying stuff:)
cheers
cheers
I am planning to make some improvements in the way we obtain particle density information for scaling the emissive power output from volumes. At the moment we use whatever the absorption grid is set to, as particle density, meaning that, as absorption increases/decreases, so does temperature. We are planning to split these into two grids, so that will give more flexibility when dealing with volumes. There is also a current issue with emissive volumes, where the step length influences the brightness. We will get to this as soon as we can
- lstudios3d
- Posts: 38
- Joined: Wed Mar 08, 2017 10:55 pm
Sounds like you are having a similar issue to what I was trying to solve with getting your logs to be cut out of the alpha. From what I've been told octane can't do that at the moment and the way around that is using layers and a multi layer exr. I've been able to get something working with that but still a few issues I'm trying to figure out.