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Culling of smoke depending on view direction
Closed, ResolvedPublic

Description

System Information
Windows 10, GTX 1070

Blender Version
Broken: Blender 2.8 Alpha 2 7b271d5fc11

Short description of error
The smoke itself seems to disappear, depending on the rotation of the viewport.

Exact steps for others to reproduce the error

  1. Load up the attached .blend file
  2. Shift A to play the smoke ( let the timeline loop, takes a few seconds, in order to build the smoke sim )

After the first timeline loop, all 4 spheres are emitting smoke, but may not look like it.

  1. Rotate the viewport to see from above the wireframe cube ( smoke domain )

You will see all 4 spheres emitting smoke.

  1. Rotate around the cube, and you'll see that the smoke disappears for some of the spheres depending on the angle of viewing.

The smoke from all 4 spheres should always be visible from all angles.

Note that the culling happens with just one sphere, having more spheres helps improve the possibility that one of them will be visible.

Event Timeline

Mal Duffin (mal_cando) updated the task description. (Show Details)

If I change the camera clip start, it has an effect on the visibility of the smoke.

Philipp Oeser (lichtwerk) triaged this task as Confirmed, Medium priority.

@Clément Foucault (fclem) : not sure about smoke in regards to T56352 (atm. smoke also doesnt appear in lookdev/rendered view/ F12 render btw.), but can confirm the display weirdness...
[I am on a nvidia 970m btw.]

I can confirm too. I will fix it soon.

Hi Clément,

I tested with the old scene, but it had the same old issue.

However, when I create the scene from scratch it works - but if I then scale the box used for the domain ( s 10 ), then I see the same issue again.

Try these steps.

  1. New Scene
  2. With the default cube selected, open the Physics panel
  3. Select Smoke, then Domain type
  4. Shift A and add a UV Sphere
  5. In the Physics Panel, select Smoke, then Flow
  6. Reselect the Domain cube, and scale it by eg 10

Shift + SPACE and let the timeline run a complete loop, then rotate around the cube to see the issue.

@Mal Duffin (mal_cando) what's the build number? the buildbot are only updating around 1am. So you might have tested an old build without the fix.

I had tried to build locally, but I was getting a crash - and did indeed download the latest BuildBot build, which didn't seem to have the commit.

The crash is related to your commit ( https://lists.blender.org/pipermail/bf-blender-cvs/2018-November/116145.html ), see the call stack below ( mutex is null, the crash occurs on BLI_mutex_unlock ).

If I revert that commit and rebuild, the smoke works as expected - nice one!