Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Guillermo Leal on 2014-06-04, 02:03:48

Title: Saving floating point image gets clamped
Post by: Guillermo Leal on 2014-06-04, 02:03:48

Trying to save an exr or hdr image either trough the frame buffer or the render dialog but the image and/or elements get clamped to 1.0
not sure if this is a bug or i'm missing something.

thanks,

Guillermo Leal.

Title: Re: Saving floating point image gets clamped
Post by: Guillermo Leal on 2014-06-06, 03:44:20

well i did some further testing and the issues is if you have higher then 1.0 on the Highlight compression in the color mapping tab the image when saving it will get clamped to 1.0 even do on the corona frame buffer shows pixels much higher then 1.0.

is this a known bug?

Guillermo Leal.

Title: Re: Saving floating point image gets clamped
Post by: Polymax on 2014-06-06, 12:56:45

No bug here.

Title: Re: Saving floating point image gets clamped
Post by: Guillermo Leal on 2014-06-06, 16:34:01

You are right. the file i was having problems was an old one maybe it came from max 2012-13 that i opened in max 2014 and started to work with corona, i have merged the file into a new scene in 2014 and now it saves correctly.

Guillermo Leal.

Title: Re: Saving floating point image gets clamped
Post by: Ludvik Koutny on 2014-06-06, 16:53:55

It is not a bug. Highlight compression is tone mapping. It really physically compresses highlights. You always need to render linear output, if you want to retain full HDR information for post processing. That means leaving highlight compression at default.

Of course, it would be possible to save output without tonemapping, but then users would save something completely different than what they see in framebuffer. So say exterior during sunny day could become just flat white burned surface without highlight compression.

That being said, there should be an option to save images without tonemapping in future...