high resolution smoke doesn't collide properly with animated objects
Closed, ArchivedPublic


System Information
Windows 7 Professional 64 bit, NVidia Geforce GT 650M
also reproduced on
Windows 7 Professional 64 bit, NVidia Quaddro 2000

Blender Version
Broken: 2.69.0 r60995, also 2.70 release candidate Date: 12-03-2014 Hash: 2525f9c
working: None that I've tried

Short description of error
The generated smoke from the smoke high resolution settings doesn't seem to calculate animated collisions properly and thus spreads through
animated smoke collision objects.

Exact steps for others to reproduce the error

Smoke flow & domain is set up with animated collision object,
so just play the animation.


Lukas Toenne (lukastoenne) claimed this task.

This is not a bug. The whole point of the "HighRes" feature in smoke sim is to provide additional detail at little to no cost. This means it cannot take into account things like collision or forcefields, otherwise it would work just like regular smoke and not be a separate feature.

To use this properly your colliders have to have some thickness to them. A "zero thickness" plane like in the test file is not suitable as a smoke collider really.

Discussed this with @Miika Hamalainen (miikah), looks like this could actually be considered a bug. Unfortunately there is no good solution to the problem either way ...

Collision with animated objects clears cells marked as "obstacles" entirely, which leads to blocky appearance (just see what happens when you disable highres smoke in the example). Doing the same for highres smoke might be less obvious, but could still show undesirable artifacts (gap between collider and smoke).

Added this to the ToDo list: http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/Tools#Smoke