Forums » CentiLeo for Cinema 4D
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some questions about HDR
a few HDR seem to have something wrong
hello, when i use centileo in C4D, i feel it's so cool, especially some meterial of transmission are really beautiful.
recently i used some hdr pictures in Envmap, but a few of them seem to have something wrong, some of them are just black. and other hdr pictures in use are fine.
i wrote an email to the address in "contacts". i am sorry to bother and maybe mailbox is not a correct place to discuss for users.
looking forward to see centileo better!
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Administrator  Posts: 449
Oct 6, 2017 08:26
Hi Luey and welcome to our forum!

Sure, best place on bugreports is forum simply because it's better structured. Don't hesitate and send you messages here.
Next version we will try to imrpove materials.

We use Cinema 4D image reader to get HDR pixels but probably missed some parameters (probably the order of channels and some exposure). Please, can you send me HDR which are loaded with problems (e.g. red and black) so we can make fixes with samples. If you need, we can sign an agreement not to distribute it to others, of course we don't want to distribute it.

Best regards,
Hello Kirill and thank you for your welcome.

I have found what caused this problem.
At first I thought it might be caused by "_" in the name of the picture, but after I did some test, I found it wasn't the reason.

After that I found something. When I use a picture, it will generate a mctx0x document, it's usually so big. Especially in the use of HDR, the document will be as large as 600 MB. If the document was only 0~100, 100~300, 300~500 MB, it might be black, green or red. In short, it will have something wrong. I haven't thought my hard disk partition is full before I check it today. If there's not enough place in hard disk partition, the mctx0x document won't be created correctly.

I will keep rendering with CentiLeo and look forward to seeing it perfect someday.

Best regards,
Administrator  Posts: 449
Oct 6, 2017 11:42
Actually there is some texture caching system in CentiLeo which exploits the disk space and assumes there is a lof of disk space (better if it is SSD, but working from USB is also ok). So, the idea of this cache is to create once and store prepared texture data for potentially out-of-core texture access from RAM and later from GPU renderer. If there is enough disk space then everything should be fine even if we have 500-700MB of texture cache inside GPU and 4GB on RAM. The scene amount of textures can be very high in this case (100s of GBs). It also saves and limit RAM size for other tasks. And the other good thing is that if texture cache .mctx is built once then texture parsing is not repeated again after later program launches.

The problem of this method is that it pollutes the disk, creates raw uncompressed bitmaps out of even jpegs and so on. And we still have no utility/accounting manager to clean this thing if they become unnecessary. We plan to make compressor for this in the future and some asset manager.

Btw, the behavior you describe can be the reason of wrong HDR rendering (just the part of file is missing).
Administrator  Posts: 449
Oct 6, 2017 11:44
Yes, one 8000x4000 HDR should generate aroung 500MB file
Thank you for your reply, it's really helpful.
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