:?: Hey I am trying to get effect of tornado. I am using volume smoke solver which inherits volume field from POPs. It works well but I have problem with controlling the density. I was looking through the web and the only thing I have found is how to decrees the density over time (using Gas Calculate or Gas Dissipate). However I am looking for something exactly opposite, which is to reduce the gas diffusion/dissipation or even completely disable it. I need it since in my simulation smoke completely disappears until it reaches the other side of the container.

Thanks!

Hi!!

You can do that with a custom field that takes only the low density values and add them back every time step.

Hi alejandro, thanks for fast reply! It seems like a good solution but I am not sure how to execute it. Would you be so kind to show me how to set it up?

Thanks

Hey I tried to use Gas Field VOP where I multiply density and then clamp it. This gives me more density but still not enough.

This is he result:

http://vimeo.com/27958151 [vimeo.com]

The problem is that each time I increase velocity, the density starts dropping even faster. So when the tornado spins faster it reaches only till the half of the container, won't go further. Could you tell me guys where in smoke solver I could look for the node that is responsible for diffuse/dissipate, since I could not find it. I just don't know what to do. If I will start adding more density in Gas Field VOP it gets too heavy and blocky, when I add too less it diffuses too fast.

I am asking about the smoke solver because it seems that the density diffuse is related to the velocity field somehow. So the higher velocity the higher diffuse…