I would like to know is there any benefit to use Sky texture node / Nishita with a bg backdrop compared to a HDRi and binding sun lamp. Also if you use Sky texture is there any benefit to add Sun lapmp with exact same position... Bit confusing, but I have feeling that you get cleaner results with sky texture and backdrop...
-
2$\begingroup$ I guess Nishita (and others) is just a procedural HDRI. As for the sun it will create parallel light rays, it won't be the case for a simple white circle on a procedural or HDRI background. $\endgroup$– moonbootsCommented Sep 11, 2021 at 20:30
-
$\begingroup$ An answer comparing performance of Sky Texture vs Hi-Res HDRI would be nice :) $\endgroup$– jachym michalCommented Sep 12, 2021 at 10:30
1 Answer
The Nishita model is described in the paper Simulating the Colors of Sky. The Blender Nishita Sky model is based on an updated version of the original model, but is very similar.
The difference between a sky model such as Nishita and the use of an HDRI is that the sky model attempts to deal with the way the atmosphere filters the light. In a sky model, if you position the sun closer to the horizon, the light will be redder, than if you position it near its zenith.
Additionally, sky models attempt to account for the effect of clouds.
If you use an HDRi and a sun lamp, you would need volumetric lighting and cloud models to accomplish the same effect. You would also have to model any clouds that you wanted to appear on the horizon.