Hey,
whats that thing with hdri maps in houdini? They always look ugly. one side is heavily overexposed and the other side too dark. Doesnt really matter if I use .hdr or exr files. This image is lit with this hdr: https://cg-source.com/details_hdrisky.php [cg-source.com]…
Does Houdini have some problems HDRIs ?
5140 9 1
-
- Rosko Ron
- Member
- 184 posts
- Joined: March 2015
- Offline
-
- matthias_k
- Member
- 483 posts
- Joined: Dec. 2006
- Offline
Hmmm, everything fine here…
simple environment with hdr
maybe wrong gamme:-?
or if you exspect more contrast,
then use a COP with brightness curve?
Its simpler to detect your problem, if you attach a file :-)
If you need more control: https://www.lightmap.co.uk/ [lightmap.co.uk]
simple environment with hdr
maybe wrong gamme:-?
or if you exspect more contrast,
then use a COP with brightness curve?
Its simpler to detect your problem, if you attach a file :-)
If you need more control: https://www.lightmap.co.uk/ [lightmap.co.uk]
Edited by matthias_k - March 18, 2017 10:12:57
English is not my native language, sorry in advance for any misunderstanding :-)
-
- Rosko Ron
- Member
- 184 posts
- Joined: March 2015
- Offline
Icant just play with cops because that ruins a linear workflow. Nevertheless I tried playing with cops but that isnt helping either.
also its not contrast thats lagging but a more normalized brightness. the one side with the sun is totally overexposed, the other side just isnt providing enough light. if the hdri isnt looking overexposed anymore there rarely isnt any light left to light the scene.
Cant attache the scene, its part of a production. the hdr image is way too big for an upload here. But you can go on this side and download a hdri sample: https://cg-source.com/details_hdrisky.php?id=0066-01&pricat=sky [cg-source.com] try lighting an ocean surface with it
also its not contrast thats lagging but a more normalized brightness. the one side with the sun is totally overexposed, the other side just isnt providing enough light. if the hdri isnt looking overexposed anymore there rarely isnt any light left to light the scene.
Cant attache the scene, its part of a production. the hdr image is way too big for an upload here. But you can go on this side and download a hdri sample: https://cg-source.com/details_hdrisky.php?id=0066-01&pricat=sky [cg-source.com] try lighting an ocean surface with it
Edited by Rosko Ron - March 18, 2017 09:50:26
-
- matthias_k
- Member
- 483 posts
- Joined: Dec. 2006
- Offline
-
- dlee
- Staff
- 431 posts
- Joined: Sept. 2016
- Offline
It's interpreting the hdr values correctly as far as I can tell. The hdr files themselves don't seem to have any custom primaries either, at least not in the samples. I suspect that the values you're used to seeing is after tonemapping (the preview images on cg-source seem like they're processed).
Mantra (like most production renderers out there) simply apply gamma by default. You can try custom LUT in the viewer or try different OCIO profiles (on final rendered output, of course) until you find the one to your liking.
edit:
I did some comparison renders to show that all renderers including mantra interpret the HDR file the same way.
You mentioned on the other thread (https://www.sidefx.com/forum/topic/43521/) [sidefx.com] that Cinema4d renders it differently - I don't have access to Cinema4d, but it's possible that it's applying some custom look/display transform out of the box.
Mantra (like most production renderers out there) simply apply gamma by default. You can try custom LUT in the viewer or try different OCIO profiles (on final rendered output, of course) until you find the one to your liking.
edit:
I did some comparison renders to show that all renderers including mantra interpret the HDR file the same way.
You mentioned on the other thread (https://www.sidefx.com/forum/topic/43521/) [sidefx.com] that Cinema4d renders it differently - I don't have access to Cinema4d, but it's possible that it's applying some custom look/display transform out of the box.
Edited by dlee - March 19, 2017 12:36:09
-
- matthias_k
- Member
- 483 posts
- Joined: Dec. 2006
- Offline
-
- matthias_k
- Member
- 483 posts
- Joined: Dec. 2006
- Offline
Cinema4D is darker… maybe ground material absorption/base color, but chrome sphere is the same.
ok, it's a v14, I'm not at a machine with the latest version,
sorry in advance, if this is not helpy as reference.
ok, it's a v14, I'm not at a machine with the latest version,
sorry in advance, if this is not helpy as reference.
Edited by matthias_k - March 19, 2017 16:41:11
English is not my native language, sorry in advance for any misunderstanding :-)
-
- matthias_k
- Member
- 483 posts
- Joined: Dec. 2006
- Offline
-
- Rosko Ron
- Member
- 184 posts
- Joined: March 2015
- Offline
-
- dlee
- Staff
- 431 posts
- Joined: Sept. 2016
- Offline
matthias_k: Thanks. Those were very helpful.
Rosko Ron: It seems clear that mantra interprets hdr the same way as all the renderers we've tried so far (prman, arnold, cycles, clarisse, cinema4d, whatever's built into Modo…), so there doesn't seem to be an issue here.
My recommendation for you is to ask cg-source directly and find out what kind of tonemaps or post-processing they're applying to the images, and use those to get the desired looks.
Rosko Ron: It seems clear that mantra interprets hdr the same way as all the renderers we've tried so far (prman, arnold, cycles, clarisse, cinema4d, whatever's built into Modo…), so there doesn't seem to be an issue here.
My recommendation for you is to ask cg-source directly and find out what kind of tonemaps or post-processing they're applying to the images, and use those to get the desired looks.
-
- Quick Links