light cache multiplier

[fooprobe]

I'm a big fan of light cache, but i find it's usually too bright, and i always used to set the multiplier to around 0.7 ... now there's no multiplier. how does one deal with the overly-bright light-cache result?

[Micha]

Save the options, open the file in an editor, look for the multiplier and set 0.7, save and load to Rhino again.

(Is this the way for the render experts now to keep the UI clean? Or is there a chance to get this kind of options back? Could be nice to get a global "expert" flag to enable all the little options (like we had at VfR2). Or it could be nice to get a way to edit all the hidden options per additional list UI that can be opened.)

[fpedrogo]

You Can also change the exposure of you scene with the camera or using the VFB color correction

[fooprobe]

Thanks Micha - yes I saw that possibility but was hoping for a way to do it in UI. Fernando, exposure isn't enough as the secondary is overblown - the balance of the primary vs secondary is way off. I did find two reasonable solutions: First, it seems that pure white materials cause more blowout in secondary than previously, so using almost-but-not-quite-white materials helps a lot. Since most scenes use other materials, not just white rooms, this works ok. Also, there is an option under "Raytrace - Optimizations" to set the Max Ray Intensity - this appears to be the exact solution as it only impacts secondary rays. by default it is set to 20, setting it very low (0.2) works ok for me. However i find the contrast is very muddy, more so than in previous versions of Vray when secondary engine was set to 0.7 for instance. So using this, plus ambient occlusion, plus no pure whites, seems to be an ok workflow.

Fernando let me know if this all is consistent with how you expect people to use the software.

Thanks,

[Micha]

You Can also change the exposure of you scene with the camera or using the VFB color correction

Hi Fer,

at the real world the brightest white cause a max diffuse indirect light "reflection" of max 80%. At Vray if the user is using a white color as wall color than he get 100% indirect light bounce intensity. That cause a wrong look based on the wrong light transport intensity (the dark corners of an interior are to bright, the general look is dull and washed out). OK, he could set all white colors to something like 220, bit he would need to set all textures multiplier at 0.8 to keep the right relations. In the past the easiest way to limit the indirect light transport was to set the sec GI engine multiplier at 0.8 and anything was fine.

The multiplier could be added to the UI again or internal a multiplier of 0.8 could be used always.

-Micha

[Micha]

About what we talk? Here an example - first image based on one of my typical setups, sec engine multiplier 0.8 (white walls, GI AO). The same setup, but sec engine multiplier 1 (same like before, but exposure adjusted). The scene is much brighter, because during each GI bounce 100% of the light is transported. The look is horrible, the GI shadows are killed, only the GI AO keep some details. Please bring back the multiplier or set it a logical value like 0.8.
(I would add the multiplier 0.8 per editing the options file, but this is no good way. Please bring back the good old functionality.)

[Grigio18]

I am for put back the light cache multipler, but Micha,you should understand that the correct value is 1 for light cache, the problem in you renders is that the diffuse value should never be more then 200 in brightness, and anyhow, you can regain the shadows decreasing exposure and increasing contrast in the first rollout of the vfb corrections.
Unless you have clamped the output, in that case maybe you have lost too much information, and you need to decrease exposure in the camera settings.

But I am sure you know all this stuff, you are one of the most experienced users...

[Micha]

But if you start to use 80% color values, you need to use a multiplier for all textures too. If not, than your textures are to bright in relation to the corrected white. Exposure/contrast doesn't work for correcting the 100% light transport.

[Micha]

Hi, could the option brought back please, it's essential. I used it at all my renderings since years. Will it be at VfR 3.6?

[Micha]

I edit my basic option file to limit the GI, but would it not be a big help for new users, if the option would be available and set at 0.8? Often I see images from (new) users who doesn't know that all colors and textures needs to be set to 80% only. So, why not allow it per simple option? Here an user got to much color bleeding by the 100% light transport:
https://discourse.mcneel.com/t/issue...ection/57501/5
here a tutorial where the user doesn't know it too:
http://www.pixelstudio.nl/?page_id=18

The render life could be so easy if this option could come back. Attached where it could be placed. Also it would be nice to get control over the scene GI saturation per single option. It's great helper at VfR2, often used, since my clients like it. Please, bring back this two options. Please look at the train interior four posts above - without this option many users will get wrong results like in this example.

[ALTO]

Totally agree with Micha, these are the most missed features from v2... (i'll add also Exponential color mapping)

[konstantin_chaos]

[Micha]

Hi Konstantin, thank you for recording the video. Only the link isn't working. I'm curious.

[Micha]

I found the video link here:

https://forums.chaosgroup.com/forum/...eed-management

Right, you set the color at natural intensity below 80%. Also the override material is a great tool.

But why not add the two simple options to keep things simple? Some times I setup a nice realistic looking scene, but the designers like to get more neutral look. I could easy switch to GI saturation 0.3 and anything would be good. And the 0.8 factor would help new users to avoid to much color bleeding and light transport without to set all colors and textures at 80% level. I'm sure the most users set white at (255,255,255) and belive they get a typical, natural white and not an unrealistic 100% white. The problem is, if the user need to set white at (210,210,210) than he need to set multipliers for all textures too. If not, the relation between the 210-white and the textures is wrong.