Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] Bug Reporting => Topic started by: artech7 on 2021-10-13, 00:44:47

Title: Volume Grid causing issues when making contact with objects
Post by: artech7 on 2021-10-13, 00:44:47: I have a fairly odd issue here. I get the same in version 7 (latest) and I have tried in version 8 (latest daily build).

The volume Grid detracts from objects when it is overlapped with that object. I have an example uploaded.

Additionally, there is a visible box when the VDB is just in the "air" not touching anything.

I double checked the same VDB in Octane, no such issue.

I believe this to be bug for the Volume Loader, because when using volume materials on objects, this doesn't happen.

No global volume is being used. No volume for the PRG Sky model is being used.

OS is Win 10 (latest update).
Cinema 4D R23.008.
Title: Re: Volume Grid causing issues when making contact with objects
Post by: mmarcotic on 2021-10-13, 14:09:52: Hello,

could you also supply the scene with assets used so that the investigation gets faster?

Thanks,
Jan
Title: Re: Volume Grid causing issues when making contact with objects
Post by: artech7 on 2021-10-14, 03:28:05: Hello,

The scene is too large to upload here. Do you have another preferred way of me uploading it?
Title: Re: Volume Grid causing issues when making contact with objects
Post by: artech7 on 2021-10-14, 05:57:15: This is probably going to be a hard thing to resolve because it's intermitted. Sometimes it works fine, sometimes it doesn't.
Title: Re: Volume Grid causing issues when making contact with objects
Post by: artech7 on 2021-10-14, 06:23:36: Sorry for the multiple posts, but I think it may be an issue with the emission setting.

This is what I get when I enable emissions. It fills up the whole container for the volume Grid instead of just the vdb.
Title: Re: Volume Grid causing issues when making contact with objects
Post by: mmarcotic on 2021-10-14, 10:16:41: Hello,

there is an up-to 10GB upload here: https://www.dropbox.com/request/TxIykqXBaJnRvWIwOypP

Additionally, it seems that you are using "Constant" as the channel option inside Emission (the box filled), try switching that to some other option.

Thanks,
Jan
Title: Re: Volume Grid causing issues when making contact with objects
Post by: Beanzvision on 2021-10-14, 12:22:13: If you're looking for a detailed article on the volume grid with each setting explained, please see our article here: https://support.corona-renderer.com/hc/en-us/articles/4402435100945-How-to-use-the-Corona-Volume-Grid-in-Corona-Renderer-for-C4D-

Unless your volume object is an explosion etc, I don't think you need to use ''emissions'' for general clouds.
Title: Re: Volume Grid causing issues when making contact with objects
Post by: artech7 on 2021-10-15, 03:42:08: I'm quite aware of how to use the volume grid. It's just odd that sometimes this issue pops up and sometimes it doesn't.

For instance, (https://s3.amazonaws.com/cdn.freshdesk.com/data/helpdesk/attachments/production/12099015327/original/VDB.png?response-content-type=image%2Fpng&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAS6FNSMY2XLZULJPI%2F20211015%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20211015T013807Z&X-Amz-Expires=300&X-Amz-SignedHeaders=host&X-Amz-Signature=502a0a08871ad869bcd2c29a84a398567f494d084277b9364364eb2497db4a10) is another screenshot I upload for ticket #205593. Also, for reference, this issue comes up regardless of whether or not I use emissions.
Title: Re: Volume Grid causing issues when making contact with objects
Post by: artech7 on 2021-10-15, 03:51:05: I also seem to be having a pop in and out issue when moving the camera. I have attached a short video of it.
Title: Re: Volume Grid causing issues when making contact with objects
Post by: mmarcotic on 2021-10-15, 11:11:13: Corona Volume grid will not work if the camera is inside the bounding box of the object.

Thanks,
Jan
Title: Re: Volume Grid causing issues when making contact with objects
Post by: aler on 2021-10-15, 18:06:17: Quote from: mmarcotic on 2021-10-15, 11:11:13
Corona Volume grid will not work if the camera is inside the bounding box of the object.

Interesting to know, are you planning in the future, so that the camera can be inside the volume?
Title: Re: Volume Grid causing issues when making contact with objects
Post by: mmarcotic on 2021-10-18, 09:26:52: Quote from: aler on 2021-10-15, 18:06:17
Quote from: mmarcotic on 2021-10-15, 11:11:13
Corona Volume grid will not work if the camera is inside the bounding box of the object.

Interesting to know, are you planning in the future, so that the camera can be inside the volume?

It is not currently on our roadmap.

Thanks for understanding,
Jan