Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: wallybok on 2020-08-08, 16:44:03

Title: Transparent materials coming out black in the render
Post by: wallybok on 2020-08-08, 16:44:03
Hi everybody, I'm a newbie so sorry in avance if I did something stupid...
What am I doing wrong? I assigned that beautiful greenish satin glass to my sphere and on the render it is coming out black.
There is a light too in the sphere, half in half out, but that doesn't affect the look of the material.
Help...
Title: Re: Transparent materials coming out black in the render
Post by: romullus on 2020-08-08, 19:03:57
You need to make glass ball hollow (add shell modifier), then adjust its walls thickness and/or material's absorbtion depth.
Title: Re: Transparent materials coming out black in the render
Post by: wallybok on 2020-08-08, 21:29:27
You need to make glass ball hollow (add shell modifier), then adjust its walls thickness and/or material's absorbtion depth.

Why so? It should work even if the sphere is solid...In fact I did try a normal glass and it's transparent.
I have problems with not fully transparent glass or liquids, they come out black!!!
What's wrong?!
Title: Re: Transparent materials coming out black in the render
Post by: romullus on 2020-08-08, 22:07:22
Because the glass ball is very thick and absorption distance too small. All the light is absorbed inside the sphere and can't penetrate it. You can choose not to add shell modifier and just increase absorption, but i think result will be different from what you want.
Title: Re: Transparent materials coming out black in the render
Post by: wallybok on 2020-08-09, 14:48:39
Here's another example of a material that is coming out black...
The only way it doesn't become black is when i tick "Thin" but I don't want to do that cos it wont create refraction and caustics.

What should I alter to obtain a solid material but transparent?
It is strange to me that this material is not "plug and play" cos olive oli for instance i won't ever be a thin layer but always a discrete volume of liquid...

Help!
Title: Re: Transparent materials coming out black in the render
Post by: romullus on 2020-08-09, 14:54:30
(https://i.ibb.co/1dzG2MZ/320px-Paris-Tuileries-Garden-Facepalm-statue.jpg)
Title: Re: Transparent materials coming out black in the render
Post by: wallybok on 2020-08-09, 15:12:03
(https://i.ibb.co/1dzG2MZ/320px-Paris-Tuileries-Garden-Facepalm-statue.jpg)

Oh c'mon I know myself I don't know shit about this that's why I'm here looking for help...

Can you please explain what's wrong?
Title: Re: Transparent materials coming out black in the render
Post by: romullus on 2020-08-09, 15:45:28
I tried to explain you already twice, but it seems you're not interested in listening.
Title: Re: Transparent materials coming out black in the render
Post by: PROH on 2020-08-09, 16:26:07
@wallybok:
1) make sure both your system units and display units are set up correct (Press "f1" for help if needed)
2) make sure that you are modeling in correct physical scale
3) adjust the absorption distance in the material if needed
4) try to understand the help people provide you before asking the same question again

Hope it helps
Title: Re: Transparent materials coming out black in the render
Post by: wallybok on 2020-08-09, 22:24:14
I tried to explain you already twice, but it seems you're not interested in listening.

Thanks for the suggestions, but I see where to change the absorption parameter, on volumetrics and SSS it was set as SSS and I could not change the absorption value. (Sorry for being stupid...)

I set it on Volumetrics scattering now I can change it but there is not a progression changing the values. 0 is transparent 0.001 is already black.


.
Title: Re: Transparent materials coming out black in the render
Post by: wallybok on 2020-08-09, 22:30:46
@wallybok:
1) make sure both your system units and display units are set up correct (Press "f1" for help if needed)
2) make sure that you are modeling in correct physical scale
3) adjust the absorption distance in the material if needed
4) try to understand the help people provide you before asking the same question again

Hope it helps

Thanks for the reply I was being stupid with the absorption cos I could not see the tab.
I set it on Volumetrics scattering now I can change the value but there is not a progression changing the values.
0 is transparent 0.001 is already black.

1) make sure both your system units and display units are set up correct[/i][/i][/s][/s][/s] Done they are the same
2) make sure that you are modeling in correct physical scale My sphere is 180mm
3) adjust the absorption distance in the material if needed That's where I get all or nothing
4) try to understand the help people provide you before asking the same question again Yep,my fault

(I've just red that a 0 value on the absorption parameter will disable the effect).
Title: Re: Transparent materials coming out black in the render
Post by: PROH on 2020-08-09, 23:14:35
0 = off
0,001 means full color at 0,001mm

If you sphere is 180mm thick, then you need to go above that to get some transparency in the middle. Try starting at 300mm and then see how it works.
Title: Re: Transparent materials coming out black in the render
Post by: wallybok on 2020-08-09, 23:32:18
0 = off
0,001 means full color at 0,001mm

If you sphere is 180mm thick, then you need to go above that to get some transparency in the middle. Try starting at 300mm and then see how it works.

Bingo! It's very strange though cos I had to use BIG values to make it transparent like 5000mm while on the tutorials the guy set the distance at 1cm and it works for him, his sphere thingy is 100mm. (see attachment)

There is something strange on mine...

Title: Re: Transparent materials coming out black in the render
Post by: wallybok on 2020-08-10, 00:03:44
UPDATE

So...I've closed and re-opened the file and apparently the sphere was gigantic, even though on the previous session it was showing me the "correct" size. Re-scaled everything now the value I need to use to make it transparent are more sensible.

THANKS!!