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View Full Version : Fluids and scene scale problem


davegreenwood
04-18-2008, 01:46 PM
Hi, I wonder if somebody can explain something I've noticed.
I'm developing a scene with some fluids fire... When developing the fire look on it's own I had my scene scale set to the default cm. My full scene is in meter scale ( a large outdoor scene). Here's what happens. If I bring in my separate fire and scale the transform node so it fits the scene (so scale x,y,z will be 100) the fluids behave as expected. But if I build the fluid container from scratch, but so it ends up the same size and resolution as the scaled one, ie it 'looks' the same, the fire effect behaves oddly, typically burning a lot hotter, and then running out. I don't know if it runs out of fuel or dissipates too much temp, but whatever it always goes out after a few seconds. I can never seem to find the equivalent settings. I feel that some settings don't need to scale, perhaps density, while others, probably temp, need to be multiplied by some factor.
I have noticed by the way that all the example scenes I have, including the Alias Learning with Duncan, have the scene scales in cm, for example the city bomb smoke scene is only about 40cm across!
Obviously I can get by with scaling my earlier set ups, but it would be good to know how scene scale relates to the attributes in the fluids. If anyone can shed any light, it would be much appreciated.
Many thanks
Dave.

Don3Don
04-23-2008, 06:40 PM
scale is matter fluid's behavior..... from my experience..
are u sure u have 2 identical container?
cause it is different between "scale in transform node" and "size in fluidShape".
It looks the same resolution, and in veiwport...
but the simulation behavior is way different.

don.

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