Importing Blender file into Cesium

I am trying to import a blender animation file into Cesium with no luck. It brings the file in as cube (which is the domain in blender). Can anyone shine some light on what I doing wrong?

Hi - Can you share some more information about this? For example:

  • What format are you trying to upload?
  • Are you using the Blender Cesium ion plugin to upload?
  • What exactly is the “animation file”?

I have tried glb, collada, fbx, and glft. They just import a cube.
I did install the addon in blander 2.82 which had an error uploading and blender 3.1. In 3.1 it never opens the cesium window to show my files.
It’s a rendering of an explosion I created in blender.

Can you share the Asset ID for the upload? I’d like to check the options chosen for processing it.

1198503 and another is 11957588

1198503 seems to be deleted or incorrect.

11957588 - Can you double check this? The number of digits seems higher (expecting 7 digits for a recent upload).


What is the proper way to import a blender file?

Hi - Blender imports usually don’t have any issues. I think the difficulty we’re facing here is that the models that were uploaded are deleted from your account, namely 1195788. So while I can see the animation and it was processed into a glTF, I’m not sure I fully understand how it did or did not work at runtime.

Based on the source FBX, it appears to be some sort of sphere animation that is surrounding a cube in the center. So what I want to confirm is whether you tried to click play on the timeline. For example, if you open this sandcastle - Cesium Sandcastle - You can see the propeller on the plane being animated. But if you click pause on the timeline (bottom left), then the animation stops. So can you confirm whether your timeline was actively simulating?

The timeline is not simulating, and the smoke and fire does not appear.

Do you a have a way you would export something like this from blender?

the animation would look like this (single frame from render)

Are you able to share the glTF / glb file for this animation? You can either upload it to Cesium ion and share the Asset ID, or you can attach it here.

realdeal.glb (81.7 KB)

ariel3.glb (2.1 KB)

The GLB file itself does contain a cube - and this cube is so large that it encloses the animated part:

Cesium Animation Forum

The animation here seems to only consist of some disc-shaped object becoming larger. I had a short look at the result of importing that GLB into Blender, and … it looks like the original Blender scene might contain elements that cannot sensibly be exported to glTF (this could be things like particle systems or certain forms of volumetric (voxel?) objects). But that’s a guess until now - maybe it’s possible to analyze that further.

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The cube is the domain in blender for the smoke and fire. The disc and sphere are the emitters. I do believe the smoke and fire from the sphere and just smoke from the disc are volumes. Any way I can get that to work in cesium?

This may confirm my guess: If this is created with a sophisticated functionality like ‘volumetric smoke’ or things like particle systems in Blender, then this cannot be stored as a glTF asset. One could be sure if you shared the original .blend file, but for now, it looks like this was the case.

More generally, it’s unlikely that something like this can be exported into a file format that can directly be rendered in CesiumJS: As far as I know, there is no standardized format that can describe these complex structures (like emitters, particle physics etc, smoke density) generically - and even if there was, supporting such a format is probably not in the primary scope of CesiumJS.

Depending on the exact goal and requirements, you might achieve a simple ‘explosion animation’ effect with the CesiumJS particle systems. They will not be as versatile and sophisticated as those of Blender in terms of the rendering effects that can be achieved, but it may be worth a look:

So do you know of a system that does work with the volumetrics?

Can I import png files and cheat it too look like its animated

This might be possible. This concept is sometimes referred to as “Impostor”: Instead of having a complex geometry (or a volumetric object, as in your case), you can just render an image of the result. When this is properly aligned with the viewport, it can look very convincingly as if it was actually rendered. There is some older discussion about animated billboards, and drafts for a possible solution (e.g. Support for animated billboards · Issue #2319 · CesiumGS/cesium · GitHub ), but reviving this might require some experimenting…