Alembic for Unity

Hello,I just found this Alembic forum an I wonder if it is compatible with Android at this date.

Thanks in advance.

 

Ok thanks you for the info.

 

Hi!

I have a very simple issue: I import my alembic animation in Unity and it's rendered in PlayMode


But I can't see it in the Built version


I've been trying anything from using other Shaders to using URP/HDRP but it never works. What's my issue?

 

That worked! Thanks

Would alembic work on Oculus Quest 2? Or is it going to?

 

No, it does not work for android.

If you want to to target android you could try to compile alembic for android, it is open source after all (https://github.com/Unity-Technologies/AlembicForUnity), but I think nobody tackeled the task so far, so you might have to dig quite a bit to get it running. Another option is to use vertex shader animations for short clips or something like VAT for more complex stuff.

 

Any news on when Update 2.1.0 will be released?

 

Hi,

i need to bring in an animated particle sim from houdini to render in unity hdrp. The import of the alembic file works great for meshed objects but not for only rendering the particle points. The problem is, that the only shader which is working in hdrp is the Alembic/Points Transparent, which is very limited. I am not a programmer and I do not know how to write a new shader myself. For my visualization i need the be able to get the vertex color attribute from the alembic file and also an emission property in the shader.

Any idea were can I find such a hdrp shader, or better is there a shadergraph template, so I could build one myself and be able to adapt it easily to my needs.

Someone at Unity please can you provide a shadergraph solution. Would help me a lot with my projects to be able to render particle sims in realtime in unity!

 

with 2.2.0-exp.2 ,AlembicCurves seems incorrect vertex normal ,how to fixed?

 

We have a big water simulation abc exported from Houdini, when we try to import a single frame of it in Unity with the alembic importer, it crashes, we already tried with multiple versions of the package, including 2.2.0.

It crashes when trying to set the velocities into one of the UV channels of the mesh
When I disable that line, the import is succesful.

Is there something we can do to fix this? (the size of velocities is 100M+)

Code (CSharp):

1.                  
2. if (split.velocities.Count > 0)
3.                     {
4.                         m_PostProcessJobs[s].Complete();
5. #if UNITY_2019_2_OR_NEWER
6.                         split.mesh.SetUVs(5, split.velocities.List);
7. #else
8.                         split.mesh.SetUVs(3, split.velocities.List);
9. #endif
10.                     }

This is the stacktrace we get upon importing the asset:

Code (CSharp):

1.                  
2. (Filename: Packages/com.unity.formats.alembic/Runtime/Scripts/Importer/AlembicMesh.cs Line: 325)
3.  
4. Stacktrace:
5.  
6.   at <unknown> <0xffffffff>
7.   at (wrapper managed-to-native) UnityEngine.Mesh.SetArrayForChannelImpl (UnityEngine.Mesh,UnityEngine.Rendering.VertexAttribute,UnityEngine.Rendering.VertexAttributeFormat,int,System.Array,int,int,int,UnityEngine.Rendering.MeshUpdateFlags) [0x00020] in <734f0376e2f248eb86a40d3dd4ed8c0e>:0
8.   at UnityEngine.Mesh.SetSizedArrayForChannel (UnityEngine.Rendering.VertexAttribute,UnityEngine.Rendering.VertexAttributeFormat,int,System.Array,int,int,int,UnityEngine.Rendering.MeshUpdateFlags) [0x000bd] in <734f0376e2f248eb86a40d3dd4ed8c0e>:0
9.   at UnityEngine.Mesh.SetListForChannel<UnityEngine.Vector3> (UnityEngine.Rendering.VertexAttribute,UnityEngine.Rendering.VertexAttributeFormat,int,System.Collections.Generic.List`1<UnityEngine.Vector3>,int,int,UnityEngine.Rendering.MeshUpdateFlags) [0x00019] in <734f0376e2f248eb86a40d3dd4ed8c0e>:0
10.   at UnityEngine.Mesh.SetUvsImpl<UnityEngine.Vector3> (int,int,System.Collections.Generic.List`1<UnityEngine.Vector3>,int,int,UnityEngine.Rendering.MeshUpdateFlags) [0x0002e] in <734f0376e2f248eb86a40d3dd4ed8c0e>:0
11.   at UnityEngine.Mesh.SetUVs (int,System.Collections.Generic.List`1<UnityEngine.Vector3>,int,int,UnityEngine.Rendering.MeshUpdateFlags) [0x0000a] in <734f0376e2f248eb86a40d3dd4ed8c0e>:0
12.   at UnityEngine.Mesh.SetUVs (int,System.Collections.Generic.List`1<UnityEngine.Vector3>,int,int) [0x00008] in <734f0376e2f248eb86a40d3dd4ed8c0e>:0
13.   at UnityEngine.Mesh.SetUVs (int,System.Collections.Generic.List`1<UnityEngine.Vector3>) [0x0000b] in <734f0376e2f248eb86a40d3dd4ed8c0e>:0
14.   at UnityEngine.Formats.Alembic.Importer.AlembicMesh.AbcSyncDataEnd () [0x003b6] in D:\_UNITY\hdrptest2020\Packages\com.unity.formats.alembic\Runtime\Scripts\Importer\AlembicMesh.cs:327
15.   at UnityEngine.Formats.Alembic.Importer.AlembicStream.ImportCallback (UnityEngine.Formats.Alembic.Sdk.aiObject) [0x00240] in D:\_UNITY\hdrptest2020\Packages\com.unity.formats.alembic\Runtime\Scripts\Importer\AlembicStream.cs:260
16.   at UnityEngine.Formats.Alembic.Sdk.aiObject.EachChild (System.Action`1<UnityEngine.Formats.Alembic.Sdk.aiObject>) [0x00017] in D:\_UNITY\hdrptest2020\Packages\com.unity.formats.alembic\Runtime\Scripts\Importer\AbcAPI.cs:390
17.   at UnityEngine.Formats.Alembic.Importer.AlembicStream.UpdateAbcTree (UnityEngine.Formats.Alembic.Sdk.aiContext,UnityEngine.Formats.Alembic.Importer.AlembicTreeNode,double,bool,bool) [0x00041] in D:\_UNITY\hdrptest2020\Packages\com.unity.formats.alembic\Runtime\Scripts\Importer\AlembicStream.cs:188
18.   at UnityEngine.Formats.Alembic.Importer.AlembicStream.AbcLoad (bool,bool) [0x00147] in D:\_UNITY\hdrptest2020\Packages\com.unity.formats.alembic\Runtime\Scripts\Importer\AlembicStream.cs:144
19.   at UnityEditor.Formats.Alembic.Importer.AlembicImporter.OnImportAsset (UnityEditor.AssetImporters.AssetImportContext) [0x0008d] in D:\_UNITY\hdrptest2020\Packages\com.unity.formats.alembic\Editor\Importer\AlembicImporter.cs:172
20.  

Edit: We can provide the abc file that gives the issue if that would help

 

Are there still Unity developers active on this forum?
Could you please take a look at the above issue Alembic import? We can provide more details if needed.
Would creating a bug ticket be better?

 

Does Unity's Alembic support include support for metaballs aka blob meshes? The most recent mention I could find was from 2018.
https://blogs.unity3d.com/2017/12/04/adam-the-evolution-of-alembic-support-in-unity/

Ca935says:
January 5, 2018 at 10:02 pm
Really great tool!
I am importing alembic files to use in timeline for a 360 rendered movie. The reason for alembic is the mesh is changing poly count over the sequence. Think lava lamp / blob mesh. Some imports with a larger surface area are divided into smaller chunks on import. This works perfectly if the material is opaque but not if the material is transparent. lots of flashing faces etc. Is it posibble for somehow force the import to keep the mesh as one on import.

Sean Lowsays:
January 22, 2018 at 10:57 pm
Hi Ca935,
This ‘vertex-sharing’ Alembic Importer is meant for static/ constant vert count mesh, eg: face, cloth. We will keep your feedback in mind and hopefully to update more on that

 

Can not save the vertex normal in ABC? In houdini can Debug the vertex normal vector in spline lines. If can export the vertex normal in ABC,can make correct curl hair card offest the vertex position along the cross( N,Tangent).

 

This thread is nearly 4 years old, and it's getting a bit crowded in here . To make it easier to find new information, we're closing this thread. From now on, we'll update the new Release announcement thread when new versions of Alembic come out. Please create new threads using the alembic tag for feature requests, bug reports or just general discussion. Thank you!