how do i solve this?

[jdomingo]

hello guys,

i have a box and a plane with the same texture material. i just want to get a distinction between the material A and B. how do i do that?
i have lower the sun power but my material doesnt look like the correct color anymore. so i leave the sun power.
i want to get rid of the burned area and make it look like the box is separated from the plane. thanks.

[Janusz Biela]

Problem comes from...physics
You must keep rules:

- in real world doesn`t exist pure white color. If you add on this box pure white you brake rules of global illumination. Having pure white (for example 255.255.255 or close) you force photons to bounce with 100% power ...and if you will have many of that objects you will get over bright because photons doesn`t loose power!)
Solution is to use maximum RGB 222.222.222 or less especially in Exteriors where are only two sources of light (Sky and Sun).

- also tone mapping must be done correct. Human eye has perfect tone map but nobody wrote good simulation of human eye - I think this is impossible because this is dynamic, zone tone map. I suggest render with blending 50% Gamma 1.6/Exponential 3.0. Also you must reduce Physky Sun under 0.5 (this default setting is not good)

- do not control diffuse of objects! This jobe does Kray (it take information about luma from surfaces during reflected photons from surfaces) So having pure dark RGB 0.0.0 you "kill" instantly photons. Having grey RGB 128.128.128 photons lose 50% of power, etc.

- If you do not use Nodes then always keep 100% diffuse for surfaces - except reflected surfaces - then keep rules 50% Diffuse/50% reflection (always 100% total)

- If you use my Nodes then you do nothing Everything is in Auto mode...you just decide how strong reflected is surface.

- I do not use LWF because it works globally and we know almost all textures needs to be tweak (most of that: brightness) This job what does LWF is kind of "brutal" tweaking. So my solution is COLOR TOOL in nodes. By this simple Node I Tweak textures because most of them are just too bright (not all!). Generally I reduce brightens down 50-70% in COLOR TOOL. Also I tweak saturation and contrast. Software doesn`t know what level should be! This is very difficult and need a lot training but is worth.

- in exteriors generally I put stronger exposure (~3-4) and softer Sun (~ 0.4) You can add Power for Sun also 2.0 - it will help photons not to "die" fast in dark surfaces.

- also remember this render example is synthetic. After adding many objects around box (trees, ways, walls, etc) you will lose a bit general light power in scene and surfaces from box will become a bit darker darker.

[jdomingo]

hello Janusz,

thanks for your reply. i basically tried all of what you suggested before i post this test image. im using nodes on the material. i dont like the result when i make the sun to .5 that is why i set it as default 1. my material has 70% on brightness. still no luck of getting it correct.

[Janusz Biela]

I will post soon here Exterior setup. Because this is matter of power of light and tone mapping.

[ZodiaQ]

Thx again Janusz for this valuable information!

[Janusz Biela]

Yes no problem. Is good when you refreshed this topic because I do not want forget this post (there sometimes too many and I can missed request) ... will post today basic scene.

[Janusz Biela]

You can use this setup.

[ZodiaQ]

Great thx!
Btw scene reports it was saved with newer version of Physky plugin? I am using Kray 2.56

[Janusz Biela]

Great thx!
Btw scene reports it was saved with newer version of Physky plugin? I am using Kray 2.56

It is no important.

[ZodiaQ]

One question Janusz, I normally use a Dome light as fill light instead of the blue sphere in your setup.
Is the sphere better and why?

[Janusz Biela]

It`s give me more "ambient" light in scene. In Physky is quite difficult to receive less contrast render - I need for example house from shadow side more bright. Also blue color from this sphere reduce Physky Sun warm effect, render is more white balanced.
Anyway try render with and without.

[ZodiaQ]

Thx, I am already playing around, very nice!