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ChrisBore
05-06-2010, 07:33 AM
Has anybody noticed a problem with this?

It just doesn't work, there is nothing in the docs suggesting it's not supported, so I'm guessing it's a problem my end or a bug.

Chris

Duncan
05-06-2010, 10:39 PM
The dynamic offset and resolution are not set by the current initial state file, so if you run an auto resize fluid several frames and set initial state the resolution will not match the start resolution of the fluid and the initial state will be ignored.

If instead you turn off auto resize run the simulation and set initial state you can then turn auto resize on and the initial state will still work ok.(because it matches the start resolution of the fluid)

At some point we may add the ability to set initial state from the auto resized fluid, which would then override the position and resolution of the fluid at the start frame. One can cache then append to cache of an auto resized fluid which might be a workaround in some situations.

Duncan

destruct007
05-07-2010, 01:55 AM
thanks for the heads up! That will save some time, when that issues would have arisen.

ChrisBore
05-07-2010, 06:24 AM
Cheers for the info Duncan, that makes sense as to why it wouldn't work.

Chris

efecto
05-07-2010, 10:26 AM
Having that feature would be great! Thanks Duncan.

republicavfx
05-10-2010, 05:27 PM
im having a problem with flickering in my animation.....im thinking maybe its because of resizeing because it seems quite pronounced. id be happy to discover it was user error.

im emitting old style particles on a curve flow and emitting fluids from that...ive attached scene here if any of you guys have an idea. cheers

video example here: http://www.vimeo.com/11625616

converting still at vimeo.........

Duncan
05-10-2010, 06:09 PM
im having a problem with flickering in my animation.....im thinking maybe its because of resizeing because it seems quite pronounced. id be happy to discover it was user error.

im emitting old style particles on a curve flow and emitting fluids from that...ive attached scene here if any of you guys have an idea.....

Make sure you have no edge dropoff(it is on by default). The dropoff is relative to the resized boundaries and as these boundaries jump on can see a flicker. One other problem is having a resize threshold that is too high. With particle emitters it should not be higher than what is emitted by a particle or it will wipe out that emission.

Duncan

republicavfx
05-10-2010, 06:48 PM
ok that was what i was thinking...however, im worried about seeing square voxels at the edges. is that simply a matter of upping the resolution? i usually just fade out the edges as u suggested not to do lol

Duncan
05-10-2010, 08:36 PM
If you get a lot of fluid pushing at a boundary faster than it can expand then you can see edges expanding (in voxel sized jumps). However if the flow is smoother the boundary will jump when the first voxel with density is encountered so you won't see a hard edge. Currently the fluid will contract multiple voxels at a time but will only expand one voxel at a time (unless it is expanding to fit emitters/particles). If the expansion is driven by a moving emitter or particles then you should be OK. If however your simulation is moving much faster than 1 voxel per timestep and the expansion is driven by the fluid solve then you may see hard edges in addition to boundaries that affect the flow. In such cases you can create dummy emitters and keyframe their positions ahead of the flow to "manually" expand the fluid more than 1 voxel per step. (this technique is described in the doc)

Duncan

Duncan
05-10-2010, 08:40 PM
Another flicker issue I just remembered... avoid using the internal light or ambient diffusion with auto resize fluids(i.e. always have real lights ON and ambientDiffusion = 0). There is currently a bug where the bounds in mental ray for these is incorrect which can cause flickering lighting along the boundary.
Duncan

republicavfx
05-10-2010, 11:09 PM
thanks... think i had all that turned on lol for triple good flicker

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