OTOY Forums

High dynamic range rendering or HDRR?

Here's one idea, or could I dare and ask for a request

Apparently this has been around for the games such as half life 2? And now I've seen this option in tom clancys splinter cell conviction.. anyways, the graphics on this game look really really good, using the unreal engine, and been thinking it's all GPU so there is probably an algorithm to do this with octane render as well.

Can we get one for octane? I was using the HDR technique manually a few times like you would do when using DSLR camera. And comes very useful when doing interior scene near a window for instance, so you can lower the exposure in the window and get a good exposure inside.

HDR is supposed to use a couple of pictures with different exposure rates, one set on normal exposure few with higher exposures and a few with lower exposures, and using software like Photomatix or Photoshop combine those pictures into one, and you can tonemap the picture at the end, set the brigthness in the shadows and so on. It's really great stuff. So here's one idea (I haven't seen any similar request I guess), not to pressure you into doing one more thing for the next build, but I think this thing can be done realtime in Octane as I've seen unreal engine uses it for games.
Am I correct to assume the algorithms can be done inside octane as well..

HDR means, i our case, not working with 24bpp 0-255 colour but floating point, eg rational numbers between 0 and 10000+, as in the real world.
Octane already does this and works like it internally.

The camera tonemapper in octane converts the image to a 24bpp 0-255 range so it can be show on a monitor, with the exposure and other controls.

Radiance

radiance, i love reading your technical explanations of how octane works. it is like a different language to me, but i still love it

Jack

radiance wrote:HDR means, i our case, not working with 24bpp 0-255 colour but floating point, eg rational numbers between 0 and 10000+, as in the real world.
Octane already does this and works like it internally.

The camera tonemapper in octane converts the image to a 24bpp 0-255 range so it can be show on a monitor, with the exposure and other controls.

Radiance

OK this is like a robot would explain it, I didn't get it all .. but I guessed octane already had something similar implemented but I figured it's not the tonemapping that I used in photomatix, and you can control a lot more things with that.. HDR usually feels warm and octane feels like that, I guess there should be more control for the tonemapping feature, like manual control for shadows brightness and more of those things.. That feature is implemented pretty well, still could do with more flexibility, I loved it when I found out I can change the mood of the render with just changing the values for the tonemapper, but I usually end up flicking 10 of those settings until I think it's good enough.. still I could do more with external software, not saying your tonemapper sucks, but put it on a to do later and refine list

Octane should support saving the render in a HDR format (OpenEXR preferably), so that artists can do the tonemapping in external applications. Despite the very good quality of Octane tonemapper, this is a must-have feature.

Also, this way is unnecessary to implement additional tonemapping features in Octane, although I wouldn't mind them

that would be a good option, I think someone asked for it already, I guess it would be great to have access to more tonemapping options, it's good, but we want better, still it does not behave like HDR would, like perfect exposure on the sky the middle and foreground of a picture.. that is what to aim for.. or render the interior and get perfect exposure through a window without brigthness going to 100%, well it is better now with the mesh lights but still, consider the idea of a perfectly automated rendering engine, I have a feeling that just a bit more work on this technique would go a long way

I also vote for hdr file output. The tone mapping inside octane is not very convenient and I also would like to have a separate shadow darkness slider.
As regard of modern games, they often use hdrr just for an excessive contrast with almost no proper tone mapping. This makes them looks rather “low dynamic range” and something opposite to what you described in Photoshop technique.

.exr or .hdr would be nice - i agree.
on the other hand i have to disagree on what has been said - well, some at least.
because - lets not forget that an hdr image looks fake. windows ARE blown out to our eyes.

still - i think exr/hdr files would give us the opportunity to (for instance) decide at what point to convert to an 8bit, within our working-pipeline, by ourselves.

colin

it's on the list (has been for a while), together with a timed save (eg save every X minutes)

Radiance

Also would be nice to have an alpha channel rendered to both png and exr automatically. Let it be a second render if it's not possible to do at the same time. I am just a bit tired of applying black material to each slot for the whole scene.