Comments on: Shadow Mapping Summary – Part 1

By: Milos Bazelides

Milos Bazelides — Sun, 27 Dec 2015 22:13:02 +0000

Thanks for a very interesting and informative article. I’m very late to the party but one thing that worked for me in the past is a simple hybrid between
normal offset and slope scaled depth bias. I don’t modify vertices at all because it creates problems on its own. Rather, I simply push depth values proportionally to sqrt(1 – viewNormal.z * viewNormal.z) where viewNormal is a surface normal transformed to light’s view space. This is something that can be easily calculated in vertex shader while rendering shadow map. It still doesn’t resolve sampling artifacts at grazing angles (I believe no “traditional” method really does) but it generates usable depth biases to such degree that using other types of bias is often not even necessary. Where grazing angle artifacts are considered a problem I simply attenuate shadows at such angles in my lighting pass.

By: Oscar Taylor

Oscar Taylor — Wed, 23 Oct 2013 23:13:46 +0000

I am so excited to play this game when it comes out. The Witness is one of the few games I am looking forward to in 2014.

By: sh4dow

sh4dow — Thu, 17 Oct 2013 09:03:14 +0000

Hm… I don’t know what the structure that is casting a shadow in this screenshot looks like. But based on what one can see, I would assume that the distance between the shadow caster and the shadow catcher on the top left is smaller than the distance in the center of the image (where the character’s silhoutte can be seen). Yet, the character’s shadow appears to be ultra-crisp versus the shape top left being blurry. But obviously, shadows should get softer with growing distance between shadow caster and catcher, not the other way around?

But… as I said in the beginning… maybe whatever casts a shadow on the top left is further away than I would assume. Or maybe this is even a WIP screenshot from when you were still figuring things out?

At any rate – love these little bits of actual development documentation that you guys release here sometimes!

By: Hemlock Drew

Hemlock Drew — Wed, 16 Oct 2013 20:14:38 +0000

The Witness Update on the Playstation Blog!!

http://blog.us.playstation.com/2013/10/16/the-witness-on-ps4-tiny-details-in-a-very-big-world/

Hemlock Drew, giving you the news you want!

By: Matteo

Matteo — Tue, 15 Oct 2013 09:30:32 +0000

I was wandering if a mixed system of shadow volumes for achitechture and shadow maps for vegetation would be better given the sleek design of some interiors… But i’m a complete newbie as long as shadows are concerned.

By: Hemlock Drew

Hemlock Drew — Sun, 13 Oct 2013 18:22:55 +0000

Great post! Really thrilled to see that shadow, very exciting!

By: Adam Bogocz

Adam Bogocz — Wed, 25 Sep 2013 06:00:32 +0000

In reply to Sami. Well, there is definetly water :) It depends on how much it will reflect I guess.. and I would say that there are mirors( I think that light beam is bounced by some mirror(s) is some video) but the question is, if there will be mirrors tiltet to the angle you could see yourself.. maybe at the end of the game ? :D

By: Sami

Sami — Wed, 25 Sep 2013 01:01:40 +0000

In reply to Adam Bogocz. I also noticed that. I think most people had already assumed the character to be human, but the fact that he has a proper shadow that will probably be seen more than once in the game makes it even more realistic and immersive. Even though you don't see the character directly, you see their outline and it enhances the idea that you really are wandering around an island. This makes me wonder, might there be any mirrors in the game?

By: TastyTexel

TastyTexel — Tue, 24 Sep 2013 18:18:08 +0000

“For the most part it is scattered in obscure power point presentations, random some blog posts,[…]”
You probably haven’t sumbled over Real-Time Shadows: http://www.amazon.de/Real-Time-Shadows-Elmar-Eisemann/dp/1568814380/ref=pd_sim_eb_5 ;)
I can really recommend this one.

By: Adam Bogocz

Adam Bogocz — Tue, 24 Sep 2013 05:59:50 +0000

Thanks for interesting post, I will be happy to read part 2. Anyways, I see from the picture you posted that we may consider that “The Withness” is definetly human and for 90% a male :D

By: Ignacio Castaño

Ignacio Castaño — Tue, 24 Sep 2013 02:41:06 +0000

In reply to fluffy. Of course. Thanks for the catch!

By: Stephen Hill

Stephen Hill — Tue, 24 Sep 2013 02:37:53 +0000

Thanks for the post Ignacio!

I’d been meaning to write up some thoughts on shadow cascade placement too, but you’ll probably beat me to it. In any case, I look forward to part 2. :)

Michal Valient also did a good job of collecting some tricks here:
http://www.dimension3.sk/2012/09/siggraph-2012-talk-shadows-in-games-practical-considerations/
(It’s not quite a “random” PowerPoint, given that it was in the Efficient Real-Time Shadows SIGGRAPH course.)

By: fluffy

fluffy — Tue, 24 Sep 2013 02:37:48 +0000

Should that “poison” distribution be “Poisson”?