KeyShot Forum

Technical discussions => General discussion => Topic started by: ohashi3d on October 23, 2010, 10:40:16 PM

Title: Ground shadows by transparent objects
Post by: ohashi3d on October 23, 2010, 10:40:16 PM
I've noticed several issues concerning to "Ground shadows" in KeyShot 2.1.21(WinXP32bit).


...yeah confusing and complex a little, so I attached several images and
sample bip file.

In test_101023_01.png:
Box#1 and #2 are same setting as 100% white "Diffuse" material.
Plate#1 is "Glass" material (two sided), and plate#2 is "Solid Glass".
Box#2 is bright nearly same as box#1, but the ground below plate#2
is dark...looks failing to catch the light through plate#2.
And, plate#1 has a label but keep transparent for ground at this time.

In test_101023_01.png:
Once saved and re-opened the bip file...plate#1's transparency for
ground is lost...plate#1 projects dark shadow same as plate#2.
(But in case of no label on "Glass", transparency is sustainable after re-opening.)

In test_101023_03.png:
Plate#1 is set as "Glass" by drag-and-drop operation from Material Library at first.
Then double-clicking plate#1 and changed to opaque material.
But plate#1 is still transparent for the ground.

In test_101023_04.png:
Once saved and re-opend the bip file...irregular transparency of plate#1 has gone.

...hmm, interesting but strange behaviour :-[

Thanks in advance,
kyosen
Title: Re: Ground shadows by transparent objects
Post by: guest84672 on October 24, 2010, 07:39:44 AM
We will check into this. 2 things, though.

- Make sure that you check "two-sided" when using the "Glass" material
- Check "Ground indirect illumination" in order for glass not to cast a shadow.

In addition you want to increase the raybounces so you get rid of the blackness in the glass.

Thomas
Title: Re: Ground shadows by transparent objects
Post by: ohashi3d on October 24, 2010, 08:10:08 AM
Hi Thomas,

> - Make sure that you check "two-sided" when using the "Glass" material
--
Yes, I set "two-sided" as shown on my sample bip file.

> - Check "Ground indirect illumination" in order for glass not to cast a shadow.
--
Oh, OK...yeah enabling "Ground indirect illumination" may be one solution.
I feel ground illumination is too shiny a little, though...

> In addition you want to increase the raybounces so you get rid of the blackness in the glass.
--
Hmm, blackness in the glass is another issue which I intended to post in near future.
I feel numbers of raybounces may be not fundamental solution, so far...

Anyway, thanks for your quick response!
kyosen