A Little Help Understanding HDRI Environments in Daz Studio ...

thedoctor

I've really appreciated both the interior and exterior apopcalyptic HDRI sets by dumor3d as a way to achieve a realistic scene with HDRI background. Recently I received a commissioned project that justified my client forking over the $119 for the Dosch 3D HDRI "Vast Landscapes" set and I was looking forward to having these professionally produced HDRI scenes in my collection. I've read several HDRI tutorials and have used HDRI environments in other 3D software so I'm aware of the concept of high dynamic range imagery. Unfortunately, now that I'm attempting to use these new toys I find that there seems to be a terrible disconnect between the dome background and the lighting of my scene. In the attached images I've placed a figure in a fresh scene with default Daz Studio settings. When I bring in the Dosch HDRI environment the background is terribly washed out and my figure is under exposed. The second image shows how adjusting the Tone Mapping settings and environment intensity does not rectify the situation and the disparity between figure and background lighting can't be balanced. Just as a test, I found one of the dumor3d apopcalyptic HDRI files and simply replaced the Dosch3D hdri file. As you can see from the bottom image, immediately there is harmony between the figure exposure and background lighting. 

Certainly, the Dosch 3D HDRI products are well known and respected so I have no doubts about the quality of these backgrounds. I assume I'm missing something with regard to how I use these HDRI images with Daz Studio to make them work properly. Can anyone with more experience using HDRI imagery in Studio help me out? Many thanks!

Fishtales

In the first image the light coming from the HDRI is high noon, all the shadow is below his feet and the light is shining from the top down. In the last image the light is coming from in front of him so is lighting him up.

To deal with the washed out look go to the Environment Tab and lower the setting for the Environment Map and/or Environment Intensity.

thedoctor

UPDATE: The Dosch HDRI collection has three resolutions for each spherical map. I've discovered the two lower resolution spherical maps are substantially different in terms of illumination. Check out the attached image. Both images have the same settings. The only difference is the top image uses the Dosch low resolution HDRI file while the lower uses the high resolution HDRI spherical map. I also confirmed this by opening each HDRI file in PhotoShop where you can clearly see a huge difference in brightness of the lower resolution HDRIs compared with the high resolution map. 

Fishtales

The low res one is for lighting only the high rejs is for lighting and background.

prixat

Sounds like the HDR files are supplied as a set, to be used together in multiple Environment domes with compositing rules for each dome. The HDR filenames may give an indication for their intended use.

Thats good for Biased renderers, not so good for Iray where we only have the one dome and extremely limited compositing.

Fishtales

prixat said:

Sounds like the HDR files are supplied as a set, to be used together in multiple Environment domes with compositing rules for each dome. The HDR filenames may give an indication for their intended use.

Thats good for Biased renderers, not so good for Iray where we only have the one dome and extremely limited compositing.

The lower resolution one is when all you want is the light, the hires one is when you want the light and the background. It saves on memory and resources.

thedoctor

Thanks for your help @Fishtales.

Fishtales

thedoctor said:

Thanks for your help @Fishtales.

You're welcome.