Motion Blur Issue with Alembic in Arnold for Cinema 4D

[abdoukhoudoss365]

Hi everyone,

I'm encountering an issue with motion blur in Arnold for Cinema 4D when importing a simulation from Houdini in Alembic format. Here are the details of my workflow:

1. Exporting from Houdini:

   • I exported my simulation in Alembic format, including the velocity attribute (v).

2. Importing into Cinema 4D:

   • I imported the Alembic file into Cinema 4D and verified that the attributes are present.

3. Configuring Arnold:

   • I enabled motion blur in the Arnold render settings.
   • I configured the motion blur parameters, including "Shutter Start" and "Shutter End".
   • I added an Arnold Properties tag to my object and ensured that motion blur is enabled.

Issue:

• The motion blur works inconsistently: it appears correctly on some frames and disappears on others.

[peter_horvath · Accepted solution]

For your screenshot it looks like motion blur is calculated based on the vertex position instead of using the velocity vector. When you import the Alembic into Cinema 4D, does it mean you load it via the Arnold Procedural object, or do you use the native Alembic import that created the geometry in the scene with the attributes as Alembic Tags?

[abdoukhoudoss365]

Oh, thank you for your response. I tried importing with Arnold Procedural, and I think it's working very well. I didn't know about this technique.