Learning Forum

[mpr7366]

Dear ANSYS Support Team,

I am writing to report an issue encountered while performing a one-way fluid–DEM coupling workflow in ANSYS Rocky 2025 R2 using point-cloud data .

When importing the Transient Static Point Cloud sequence, the first frame (t = 0 s) displays correctly; however, at the next time step (t = 0.01 s), the cloud becomes a randomized cube-like distribution with no physical pattern.
Each file (30m_cloud0.txt, 30m_cloud1.txt) imports properly when used individually as static clouds, so the problem appears to be specific to Rocky’s transient point-cloud reader.

The transient definition file used in the import has the following format:

 

start_time stop_time file

0.00 0.01 30m_cloud0.txt

0.01 0.02 30m_cloud1.txt

I have attached a detailed  two screenshots showing the frames and flow field at 0 sec and 0.01 sec.
The workflow uses a custom Rocky external module for one-way fluid–DEM coupling.

Could you please:

1. Confirm whether there are known issues with transient static point-cloud imports in Rocky 2025 R2 (especially for tab-delimited or large files > 20 million points).

2. Verify the expected file format and delimiters for transient point clouds.

3. Suggest possible workarounds .

Thank you for your time and support.

Kind regards,

Madan B K

[Jackson Gomes]

Dear Madan,

There is a known issue in Rocky 2025 R2 (25.2) affecting Transient Static Point Cloud imports, where only the first frame loads correctly. This will be fixed in 2026 R1 (26.1).

Workaround: import each file as a separate static point cloud and manually set the start/end times for each frame.

 

Hope this helps! 

If you'd like to explore more learning materials about Rocky software, you can find them here: https://innovationspace.ansys.com/ais-rocky/

 

Warm Regards,

Jackson