Tools > ply2vrmesh bug + C4D Vray Proxy bug

[imdb]

Using ply2vrmesh tool to convert an Alembic (abc) file with velocity data, results in a small vrmesh file.

Converting a regular abc file seems to work without any issues. It fails when velocity data is present.

Here's the output I get no matter what parameters I pass.

test8.abc is 2.7 gigs. I'd attach it here otherwise.
test8.vrmesh.zip

Coincidently. If you attempt to use this test8.vrmesh using VRAY Proxy. Cinema 4D crashes.
_BugReport.zip

[valentin_leondiev]

Hello imdb ,

Apologies for the delayed reply.

I just tried it but I couldn’t replicate the crash and everything looks okay on my end with the .vrmesh file.

Can you please provide me with the alembic file that this issue happens with so I can investigate it? You can share it with a Google Drive link (make sure you grant us permissions to access the file) or WeTransfer for example.

[imdb]

Hello imdb ,

Apologies for the delayed reply.

I just tried it but I couldn’t replicate the crash and everything looks okay on my end with the .vrmesh file.

Can you please provide me with the alembic file that this issue happens with so I can investigate it? You can share it with a Google Drive link (make sure you grant us permissions to access the file) or WeTransfer for example.

It is the same alembic file from the other bug report. If you attempt to convert that abc file using ply2vrmesh it will not produce a viable .vrmesh.

[valentin_leondiev]

Hello imdb

I checked the bubbles alembic file from this forum thread ( https://forums.chaosgroup.com/forum/...specific-frame ) and indeed when I tried to convert the file, it resulted into a very small .vrmesh file.

Ply2vrmesh has an option to specify the attribute name of the velocity attribute if it's different from the standard “v”. I loaded up the file in Houdini to check what the attributes are for the velocity and I found out that it was named “Velocity” however the format was different. See the picture below.

http://ftp.chaosgroup.com/support/sc...6_12-13-36.png

The format of the velocity seems to be in RGBA format, which is different from the standard XYZ. See the image below of how an alembic with velocity I created looks like and converts without any issues.

http://ftp.chaosgroup.com/support/sc...6_12-18-59.png

I managed to convert in Houdini the velocity attributes from your alembic to look like mine. Afterwards the ply2vrmesh converted your alembic correctly and it also looked fine in Cinema4D when I loaded the .vrmesh file in a proxy. See the image below.

http://ftp.chaosgroup.com/support/sc...6_14-25-56.png

Can you please let me know from where did you export the alembic file from and is it possible to modify how the velocity is exported?

From my test, I assume ply2vrmesh expects a different velocity format and fails to convert correctly because of that.

[imdb]

Hello imdb

I checked the bubbles alembic file from this forum thread ( https://forums.chaosgroup.com/forum/...specific-frame ) and indeed when I tried to convert the file, it resulted into a very small .vrmesh file.

Ply2vrmesh has an option to specify the attribute name of the velocity attribute if it's different from the standard “v”. I loaded up the file in Houdini to check what the attributes are for the velocity and I found out that it was named “Velocity” however the format was different. See the picture below.

http://ftp.chaosgroup.com/support/sc...6_12-13-36.png

The format of the velocity seems to be in RGBA format, which is different from the standard XYZ. See the image below of how an alembic with velocity I created looks like and converts without any issues.

http://ftp.chaosgroup.com/support/sc...6_12-18-59.png

I managed to convert in Houdini the velocity attributes from your alembic to look like mine. Afterwards the ply2vrmesh converted your alembic correctly and it also looked fine in Cinema4D when I loaded the .vrmesh file in a proxy. See the image below.

http://ftp.chaosgroup.com/support/sc...6_14-25-56.png

Can you please let me know from where did you export the alembic file from and is it possible to modify how the velocity is exported?

From my test, I assume ply2vrmesh expects a different velocity format and fails to convert correctly because of that.

I've exported using OpenVDBMesher (Insydium X-Particles). There's no option to change channel name.

Interestingly enough, if I open Vray Proxy to work with unconverted file, Vray Proxy is able to read velocity data without any issues.

[imdb]

Attached alembic file causes a crash in libVRaySDKLibrary.dylib when I attempt to load it into Vray Proxy. I am using Jul 29th version S24 C4D on Mac.

It is a poor quality file, not actually trying to use it. However, it should not cause unhandled exception within the dylib.

https://drive.google.com/file/d/1Uc-...ew?usp=sharing

[valentin_leondiev]

imdb

This is an issue with the ply2vrmesh tool. This is a standalone tool which is distributed with all integrations of V-Ray. I have reported the issue in our internal bug tracking system (VC4D-1055) I will notify you when we have an update about this issue.

Can I ask why are you trying to convert the alembic file that way? What are you trying to achieve? There might be a better way to do that.

The file you shared in your last post hangs on load, and with the same build as yours for Cinema 4D R24 gives me the same error message. Converting the attributes using VEX in Houdini resulted in the file being load up correctly. We are investigating why these issues occur.

[imdb]

imdb

This is an issue with the ply2vrmesh tool. This is a standalone tool which is distributed with all integrations of V-Ray. I have reported the issue in our internal bug tracking system (VC4D-1055) I will notify you when we have an update about this issue.

Can I ask why are you trying to convert the alembic file that way? What are you trying to achieve? There might be a better way to do that.

The file you shared in your last post hangs on load, and with the same build as yours for Cinema 4D R24 gives me the same error message. Converting the attributes using VEX in Houdini resulted in the file being load up correctly. We are investigating why these issues occur.

I was looking for a reliable way of working with alembic files.

V-Ray proxy + alembic file handling has a lot of bugs. So far I've seen:
- crash of C4D when there's an attempt to use Full Geometry
- playback visible in editor does not match what gets rendered
- overall instability, Using separate project I have to test loading new alembic files. Sometimes it'll just crash during the load.

So I was looking to see if stability & handling improves if I convert to a native file format.

Also there's some bug which affects distributed render node running on windows, native alembic format presence, will simply have distributed node exit V-Ray process, there are no errors in the logs, it simply exits. So then C4D interface is stuck 'rendering' when in reality, there's no distributed node running.