View Full Version : HDRIs to FUzzy to use as background

08 August 2002, 07:50 AM
I've used HDRIs for lighting scenes with pleasing results.

It would also seem logical to use this image as the spherical backgorund or environment map. However all the HDRI images I have used ( downloaded from the internet) end up being too fuzzy or low rez for a decent render.

Are there any HDRI images of scenes that are available that dont have this problem or does a scene need to be photographed separately at high resolution to get a decent result.

Also should hdri images be used in the environment slot or mapped to a sphere as the results vary significantly. I am using max and rendering with vray.


08 August 2002, 10:00 AM
Hemisferical Backdrops need a significant resolution to not become fuzzy.
if you render at 800x600 and your horizontal camera view angle is 45 degrees....then you will need a minimum of 6400 pixels horizontally and about a quarter vertically....but twice that would be better, unless you defocus your cam.
Are there any free hdris that big?
marlin panoramica hemisferical skies have about 9000 pixels...and still look somewhat fuzzy.
so: yes you will need lots of photographs or a hires panorama camera.

08 August 2002, 05:55 PM
I'd say, that hdri map is great for lighting, but not too great for bg.
It also depends on what you want in your scene. But i'd say that you need to use hdri as light only.
and use something else for bg.
also hdri's are possible to map both in envy slots, and on objects.
For instance, if you want a light coming from a certain direction, you create a u shaped plane and position it so it lights like an area light.

08 August 2002, 10:18 PM
If you use a differnet environment than your HDRI, dont you think that sort of defeats the purpose, except that you get nice object lighting that does not relate to the background.

Is there any point in using HDRI unless you have a budget large enough to photograph or model the environment to produce a high res background?

Are the Marlin Backgrounds HDRIs or just texture maps, there being a significant difference between the two.

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