Smoke appears at an offset above the emitter (Scaled Mesh Issue) #28971

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konfuse kitty · 2011-10-19T13:55:50+02:00

konfuse kitty commented

2011-10-19 13:55:50 +02:00

%%%This is tested in 2.60 r41113 on Ubuntu 10.10, but it's older than that:

Create a plane
Press Space and type "Quick Smoke"
Run animation until about frame 40, so that a good amount of smoke appears
Hit Render

The smoke will appear smaller than in the viewport and above the plane.

Please note that this problem is not limited to Quick Smoke, but I'm using the command for ease of illustration. The problem is there when creating smoke manually, and nothing I've tried fixes it. I tried just the default cube for the domain, or cube resized, different objects for emitters, different settings - the smoke always appears offset and smaller.%%%

%%%This is tested in 2.60 r41113 on Ubuntu 10.10, but it's older than that: - Create a plane - Press Space and type "Quick Smoke" - Run animation until about frame 40, so that a good amount of smoke appears - Hit Render The smoke will appear smaller than in the viewport and above the plane. Please note that this problem is not limited to Quick Smoke, but I'm using the command for ease of illustration. The problem is there when creating smoke manually, and nothing I've tried fixes it. I tried just the default cube for the domain, or cube resized, different objects for emitters, different settings - the smoke always appears offset and smaller.%%%

konfuse kitty commented

2011-10-19 13:55:50 +02:00

Changed status to: 'Open'

konfuse kitty commented

2011-10-19 16:12:02 +02:00

%%%I think I have found a workaround fix (and therefore the cause of the problem). It seems that the relation of Scale and Dimensions of the Smoke Domain cube must be x2 for the smoke to appear correctly. By default the relation is x4: Scale = 3x3x2, Dimensions = 12x12x8.

Perform the four steps as outlined above
Return to frame 1
Still in Object mode, scale the Smoke Domain cube up by x2
Tab into Edit mode and scale the cube back down by 0.5

Now when you play the animation or bake, the smoke appears around the emitter, same as in the viewport.%%%

%%%I think I have found a workaround fix (and therefore the cause of the problem). It seems that the relation of Scale and Dimensions of the Smoke Domain cube must be x2 for the smoke to appear correctly. By default the relation is x4: Scale = 3x3x2, Dimensions = 12x12x8. - Perform the four steps as outlined above - Return to frame 1 - Still in Object mode, scale the Smoke Domain cube up by x2 - Tab into Edit mode and scale the cube back down by 0.5 Now when you play the animation or bake, the smoke appears around the emitter, same as in the viewport.%%%

Miika Hamalainen commented

2011-10-19 19:53:26 +02:00

%%%Can't reproduce here, and sounds very strange indeed. Have you tried to load "Factory Settings"?

For me I get:
*Four steps in your first post + render leads to perfectly aligned render.

Doing those additional steps in your second post however, lead to double larger smoke below the emitter.%%%

%%%Can't reproduce here, and sounds very strange indeed. Have you tried to load "Factory Settings"? For me I get: *Four steps in your first post + render leads to perfectly aligned render. Doing those additional steps in your second post however, lead to double larger smoke *below* the emitter.%%%

konfuse kitty commented

2011-10-19 23:32:41 +02:00

%%%You're right - I loaded Factory Settings, ran the four steps, and it renders perfectly. The next steps result in smoke below the emitter.

What could it be about my setup that affects the simulation in this way? I'm lost for clues...%%%

%%%You're right - I loaded Factory Settings, ran the four steps, and it renders perfectly. The next steps result in smoke below the emitter. What could it be about my setup that affects the simulation in this way? I'm lost for clues...%%%

konfuse kitty commented

2011-10-20 09:36:38 +02:00

%%%Attaching the blend... If you load Factory Settings and open this file with Load UI checked, when you render you should see what I'm seeing.%%%

konfuse kitty commented

2011-10-20 12:53:11 +02:00

%%%Got it! In the Display settings of the Transform panel, I had Scale set to 2, not the default 1. Setting it back to 1 'fixes' it. I hope this bug gets a proper fix though, as it would be nice to be able to set the Scale, without causing trouble.%%%

Janne Karhu commented

2012-02-12 01:59:35 +01:00

%%%Oh, this is pretty nasty one. Display scaling actually effects the internal scale of the objects that are created from the add menu.

On the smoke documentation it clearly says not to edit the domain object's vertices in any way (only scale in object mode), but creating objects when display scaling is not 1.0 actually creates the objects with their vertices already edited. What the smoke documentation actually means is that any other shape than a cube with unscaled dimensions of 2,2,2 won't work correctly.

There's really nothing that can be done about this without major operations to the smoke code at this time. You just have to make sure the smoke domain is always a cube with nonscaled dimensions 2,2,2.

Closing the report.%%%

%%%Oh, this is pretty nasty one. Display scaling actually effects the internal scale of the objects that are created from the add menu. On the smoke documentation it clearly says not to edit the domain object's vertices in any way (only scale in object mode), but creating objects when display scaling is not 1.0 actually creates the objects with their vertices already edited. What the smoke documentation actually means is that any other shape than a cube with unscaled dimensions of 2,2,2 won't work correctly. There's really nothing that can be done about this without major operations to the smoke code at this time. You just have to make sure the smoke domain is always a cube with nonscaled dimensions 2,2,2. Closing the report.%%%

Janne Karhu commented

2012-02-12 01:59:35 +01:00

Changed status from 'Open' to: 'Archived'

Janne Karhu closed this issue

2012-02-12 01:59:35 +01:00

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Smoke appears at an offset above the emitter (Scaled Mesh Issue) #28971