stop lights bleaching out blacks?

# 1 23-01-2009 , 03:09 PM

Subscriber
Join Date: Jul 2008

Location: Chelmsford, Essex, UK

Posts: 1,162

Can someone give me any tips on something thats been buggin me over my last couple of projects. Ive been making guns for the past few weeks, and a problem i keep getting, is, where say, the bul of the colour map for the gun is black, or, you know, a very dark grey at least, as soon as i stick any lighting in my scene, the blacks get bleached out to a really dull grey. Ive played around with spec settings (this solved for one gun which was an anisotropic material),, ive dome lit, poly plane lit, mia physical sun lit, but always to the same result. If i want something to be well lit,to cast nice shadows, I seem to have to sacrifice to blackness of the blacks. Here is a working example in case...

Attached Thumbnails

Click image for larger version

Name: mini.jpg
Views: 279
Size: 27.6 KB
ID: 41293

Quote

# 2 23-01-2009 , 06:48 PM

Registered User
Join Date: Dec 2005

Location: Brooklyn, NY

Posts: 3,708

try looking into adding an occlusion layer.

arran3D

arran3D blog

Quote

# 3 24-01-2009 , 02:45 PM

Lead Modeler - Framestore
Join Date: Feb 2003

Location: UK

Posts: 6,287

The problem you have is the fact that all of the light sources you have mentioned here are creating a more global feel in the lighting therefore illuminating the areas you need to darken.

Without sounding patronising this really underlines the inexperience here with fundamental knowledge of lighting setups. Looking at the above image you can see straight off the bat by the ground shadow that its a globally lit issue as the shads are blue. You could use an occlusion pass but theres no point unless you understand what is happening with regards to the light sources you've mentioned, shaders do not matter here, they are irrellavent.

Try using a standard light setup first (key, fill and back light) then by using these you see how the lighting works.

Also its worth seeking out a book called Digital lighting and Rendering by Jeremy Birn - could save your life!

Jay

Quote

# 4 24-01-2009 , 02:57 PM

The Nurb Herd
Join Date: Oct 2007

Location: London

Posts: 2,381

this is my last finished piece there are 8 or 9 lights and no final gather! user added image

Quote

# 5 24-01-2009 , 03:23 PM

Lead Modeler - Framestore
Join Date: Feb 2003

Location: UK

Posts: 6,287

Superb Dom!

my point exactly, if the fundamentals are grasped then all will be good later on!

Jay

Quote

# 6 24-01-2009 , 06:52 PM

Subscriber
Join Date: Jul 2008

Location: Chelmsford, Essex, UK

Posts: 1,162

Cheers for all the replies. That leather sofa looks well good hammer.

Dont worry about sounding patronising Jay, the lessons best learned should be those that hit home hardest I guess.I did start off just using lights and using a two light set up, but it gave me the same dull grey I didnt want..Actually it does sound a bit dumb now i'm writing this. I have lee laniers advanced lighting and texturing book, and I know about three point lighting for naturalistic set ups and what not from that. Not loads, but I understand the concepts. Ive gone with the physical sun set up and adjusted the textures to suit and ive got some renders im fairly pleased with. I will say, I disagree in part about it not being anything to do with the materials because surely adjusting the diffuse/eccentricity/spec roll off settings could all make a difference? although for sure is not an all out cure. I will dig my Lanier book out next time, and see if that helps. If not i'll hunt around for tutorials or maybe the book you suggest.

Quote