KeyShot Forum

Technical discussions => Rendering => Topic started by: Speedster on September 26, 2011, 05:32:56 PM

Title: Why are renders lighter than on screen?
Post by: Speedster on September 26, 2011, 05:32:56 PM
Hi all;
For some reason, all of my renders come out lighter than as I see them on the screen.  Especially, the shadows seem to almost disappear. This has been going on for a long time, and I usually adjust in PS.  I'd rather not.  Any clues?
Bill G
Title: Re: Why are renders lighter than on screen?
Post by: KeyShot on September 26, 2011, 09:56:55 PM
You get an extra bounce of lighting with the normal offline renderer. With the realtime renderer (option in the rendering tab) you will get exactly the same image as in realtime.

-- Henrik
Title: Re: Why are renders lighter than on screen?
Post by: Speedster on September 27, 2011, 07:35:14 AM
Thanks, Henrik.  How can the extra bounce be adjusted out prior to render?  Realtime does not usually give the render quality I need for print.  I've played with gamma, and it does help the problem, but it's a lot of trial and error that my client's don't want to pay for.
Bill G
Title: Re: Why are renders lighter than on screen?
Post by: KeyShot on September 27, 2011, 10:06:39 AM
Hi Bill,

We used to have an option for that, but we ended up removing it. You should be able to achieve the darker look if you turn down the number of ray bounces in the scene (especially since it is only diffuse).

-- Henrik
Title: Re: Why are renders lighter than on screen?
Post by: guest84672 on September 27, 2011, 01:21:11 PM
Bill - did you check detailed indirect illumination in the render tab? Make sure that this is turned on. Obviously it is turned on automatically when you hit the render button.
Title: Re: Why are renders lighter than on screen?
Post by: Speedster on September 27, 2011, 05:19:25 PM
Hi Thomas-
Quotedid you check detailed indirect illumination in the render tab?
Nope, but I think you mean on the Realtime tab.  There's no such critter on the render tab.  Checking indirect makes them both the same, and way easier to tweak.  Thanks!
Bill G
Title: Re: Why are renders lighter than on screen?
Post by: Chad Holton on September 28, 2011, 08:38:54 AM
Hi Bill,

That is an awesome model! Care to share the whole rendering?
Title: Re: Why are renders lighter than on screen?
Post by: guest84672 on September 28, 2011, 08:40:19 AM
Quote from: Speedster on September 27, 2011, 05:19:25 PM
Hi Thomas-
Quotedid you check detailed indirect illumination in the render tab?
Nope, but I think you mean on the Realtime tab.  There's no such critter on the render tab.  Checking indirect makes them both the same, and way easier to tweak.  Thanks!
Bill G

Yes - that's what I meant ... sorry for the confusion.

We will change this "behavior" in KeyShot 3 ...
Title: Re: Why are renders lighter than on screen?
Post by: Speedster on September 28, 2011, 02:49:06 PM
QuoteThat is an awesome model! Care to share the whole rendering?

Hey, Chad- yep- it's almost ready for an "Amazing KeyShot".  Here's a sneak peek.  It's an on-again/off-again year long project, in between making a living.  It's a 1912 Case 40 HP Steam Traction Engine.  Lot's of research, hundreds of measurements and photos, etc.  Researched at the Antique Gas and Steam Museum in Vista, California.

4,723,927 polys.  560 MB worth of SolidWorks files, and the .bip is 186 MB. With projects like this I'm sure glad I have 1,820 GB of hard drives!

1st image she is "unrestored, just like I found her" out in the desert.  Undergoing "restoration" now.  2nd image is the color mapping. Note on the canopy I mapped it to allow for KS wood grain direction.  You can always change your mind on colors if you plan ahead. 

More to come...

Bill G
www.GouldStudios.com (http://www.gouldstudios.com)
Title: Re: Why are renders lighter than on screen?
Post by: Chad Holton on September 29, 2011, 07:27:19 AM
Thanks, Bill - looking good! That's a lot of work most people take for granted when viewing such a beast. Be sure to post a few angles showing the little details when you're ready.