Ever wondered how to light your scene? Confused as to why some stuff is dark, or too bright? Ever felt left out as your friends discussed three point lighting techniques, while you just sat there stupid with your diet coke, and they got all the babes coming over to them and … well, anyway, I signed up to write the VSE section of the wiki, but when I looked at it, there’s NOTHING there, and so I procrastinated, and instead wrote down everything I know about lighting, and added it to the wiki: http://mediawiki.blender.org/index.php/Manual/Lighting_Rigs.
As a bonus, just cause I love y’all, I included a .blend file that has the rigs already set up for you. Enjoy!
Thanks Roger, we need as much lighting information as we can get.
Did you also write the section on buffer shadows? This is one area of Blender which is seriously in need of further exploration and explanation. I think a lot of Blender users rely far too heavily on Yafray to solve all their lighting problems for them. This is great until you try and animate a moderately complex, two minute movie on a standard home computer. The same scene lit with buffers would render in a fraction of the time and Pixar claim to have avoided ray-traced lighting prior to Cars for that reason. If Pixar can make feature movies without ray tracing, we should be able to get by without it.
However, buffered shadows come with their own set of problems that seem to be undocumented. I’ve attached an example of something I come across quite regularly (I use buffer shadows all the time) and while it can sometimes be solved by messing with the clipping, buffer size, bias and samples values, sometimes (as in this case) it seems impossible to eradicate. The only way I’ve managed to “solve” the artifact problem in this scene is by adjusting the spec settings on the material - but then I don’t get the matte-finish material I want.
I think it’s a ramp or lighting thing. Cause that’s right on the terminator, just beyond where buffer lights cast shadows, cause they don’t cast shadows on faces that are turned away from them, which may mean the turned away faces are receiving light or somehow being brightened beyond that point.
Nope, definitely not reflection. There’s no ramp shaders applied either. Nothing fancy here. It is definitely related directly to the buffered shadow and Blackboe is, I suspect, on the right track with regards to the terminator. As I said, I’ve had it before, even on my avatar character, and managed to eradicate it by playing with the various options available for buffered lamps. But I’ve never nailed to solution down to anything specific and in this case, can’t even find a solution.
Interestingly, if I switch to ray shadows, I get those little black triangles that sometimes show up - and messing with the octree settings doesn’t fix them either (which I thought it should).
Sorry Roger, didn’t mean to turn this into a support thread.
@AndyD: u hijacker No, dont know about buffer shadows. I do know that if your sidelights are spots, there are these wierd shadow lines on the sphere, normal to the light source, like some sort of overcorrection for a shadow. Changing them to Hemis clears up the problem. See the .blend and change the type of sidelights to see what I mean, in the three point rig (may have to delete the key to see it clearly), which sounds very close to your problem…I assume you’ve read Manual/Buffer Shadows…
Your scene is way overlit, imho, so that’s a complication right there. As a nature painter (and a very talented one at that), I’m sure you appreciate the softness of light, and forcing blender to beat down on a scene with too much causes artifacts.
First, try killing all materials and see if you get those lines on grayness objects, that shoulld help determine if youve got a lighting problem, or a materials-interacting-with-light problem.
Then start killing lights; go back to one light, make sure it’s smooth, then add them in one by one. As they add together, reduce power in the tested ones so they merge cleanly. Notice in the wiki at one point i have power set to 1.7. 1.6 is toolow, resulting in two flares, and .18 is too much and flares the whole thing. Teeny adjustments in multi-light situations makes a huge difference in blending the light and avoiding competition.
Your scene is way overlit, imho, so that’s a complication right there. As a nature painter (and a very talented one at that), I’m sure you appreciate the softness of light, and forcing blender to beat down on a scene with too much causes artifacts.
It’s not really that bright or contrasty. I pushed it in Photoshop so as no one would miss the problem. Then I added the arrows so that those who missed it anyway still wouldn’t miss it …And thanks for the compliment.
There’s only one spot-lamp in the scene and that’s “shadow only”. The main light is a sun. … Actually, a quick test suggests that “Only Shadow” might be the culprit. Okay, must investigate further and make sure it’s not just my eyes deceiving me (it’s 1am here)
Thanks Roger. I’ll follow this path now and see where it leads. As I said earlier, it would be great to really get buffer lamps working “perfectly” as it can save hours/days/weeks of render time compared to ray tracing.
Edit: Okay, that was too easy - which is why it turned out to be wrong However, I then looked at the material since I’d noted previously that messing with the spec can deal with it (it occurs when spec and hardness are set low for a matte finish). Lo and behold what did I find there? A slider called “SBias” and the mousetip tells me it’s to “prevent terminator problems on shadow boundary”. I messed a bit and saw improvement then I shoved it all the way to the right and the problem all but disappeared! I think that’s it! (Now I just have to find out what the trade-off is - there’s always a trade-off).
Putting all this on my favorites. I’d like some instruction on shadow buffers too. I’d like someone with real know-how to do the lighting on XTIN project, but I could also benefit from increased render times when texturing.
No, dont know about buffer shadows. I do know that if your sidelights are spots, there are these wierd shadow lines on the sphere, normal to the light source, like some sort of overcorrection for a shadow. Changing them to Hemis clears up the problem. See the .blend and change the type of sidelights to see what I mean, in the three point rig (may have to delete the key to see it clearly), which sounds very close to your problem…I assume you’ve read Manual/Buffer Shadows…
…And thanks for the compliment.
However, I then looked at the material since I’d noted previously that messing with the spec can deal with it (it occurs when spec and hardness are set low for a matte finish). Lo and behold what did I find there? A slider called “SBias” and the mousetip tells me it’s to “prevent terminator problems on shadow boundary”. I messed a bit and saw improvement then I shoved it all the way to the right and the problem all but disappeared! I think that’s it! (Now I just have to find out what the trade-off is - there’s always a trade-off).