GI makes scene darker

[ProceduralFrankie]

Hello everyone,

I am trying to make the lighting of a warehouse, the set up is pretty basic:

- portal light working as envlight

- distant light

and the GI light that apparently is making the scene darker than when is swtiched off. Does anybody know how to solve this?

Thank You very Much

Frankie

MP_H_Enviroment_Problem.hipnchip.hipnc

Edited July 18, 2018 by ProceduralFrankie

[davpe]

hi, your setup is not working. you were getting no light bounce from gi lights. the reason why the picture had more light in it when you turned gi lights off, was because light bounce was computed by pathtracer which is a default "global illumination" solution in mantra. pathtracer is disabled once you turn on gi light, and bounces are computed by photon maps. photon maps are sort of an old school approach by the way... 

check the attachment for fixed scene.

cheers.

 

gilight working.hipnc

[ProceduralFrankie]

Hey, thank you Dave

sorry what needs to be done in order to make it work? Do you change setting on the gi light or on the mantra rop?

Now is creating the photom map but the render appears solid gray...

Also,  if not with photon map how would you approach the lighting of such scene with the goal of photorealism?

Thanks 

Frankie

 

 

[davpe]

this is what i get when i load the scene and hit render. photon map generation can take a while thou so you may need to wait (or make your photon count and filter/prefilter samples fewer).

actually i haven't changed any significant settings in your scene. my guess is it was just a path to the photon file on one of your lights that made it fail.

regarding suggested workflow, you can achieve photorealism by any available method, it is more a question of a way of getting there more than whether you can get there. photon maps actually is something i wouldn't discourage you from using, and particularly for interior scenes it may perform better than other illumination methods. but it's a bit dated in terms of workflow and it is somewhat more complicated to set up properly (images may appear fuzzy or may have nasty artifacts). most renders you see today are computed by pathtracing, which is an unbiased method for light transport used by most contemporary CPU renderers, including Mantra and Arnold. its' accuracy is superb and it is really easy to use, on the other hand, pathtracing is generally slower than photon maps and images may show unwanted noise, especially in scenes that are mostly illuminated by indirect light (typical for interiors or evening/night lighting). effects like caustics for example are very expensive to render with pathtracing.

both methods have it's pluses and minuses and it's up to you to consider which one is right for your needs. hope that helps.

cheers.