out of sky light
laverdet_943f1f7da1
Posts: 252
Hi!!! I have a scene, lighted mainly with sky light, and ambient occlusion, with a very yellowish hdri... and a plane, as background... is it a way to have no light from the sky on that plane, just a dedicated distant light on it, and keep its blue color "clean"??? thank you for help!!!
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There is no way to isolate specific objects from being lit by the skylight. Once you turn the skylight option on, it's going to affect everything in the scene. And if that skylight has a color to it (yellowish in your case) that color is going to wash over everything in the scene.
The only way around it would be to render them separately and maybe composite them together afterwards in another program.
A plugin from Digital Carver's Guild called SHADERS PLUS has a couple of top-level shaders that allow for excluding global illumination...
http://www.digitalcarversguild.com/plugin.php?ProductId=13
I looked at Lighting Control and Selective Lighting. Those are the only two that appear to do what he wants but neither of them seems to actually be able to do it. How does it work?
I looked at Lighting Control and Selective Lighting. Those are the only two that appear to do what he wants but neither of them seems to actually be able to do it. How does it work?
They can both do it.
Change the plane's shader tree to SHADERS PLUS --> Selective Lighting
Uncheck "Allow GI"
That's it. The shader will now not be effected by any global illumination settings.
I don't know if it helps, but the same plugin gives some other top level shaders like "Flat" and "Mask".... Assuming the "blue plane" is working as a chromakey mask, this plugin can make the blue plane a solid color - no need to light it at all.... I don't know if that is what the "blue plane" is for, but from the description of it being excluded from Ambient Occlusion and GI shadows, and lit only with one Distant Light (flatly) suggests it is being used as a color-keying mask.
They can both do it.
Change the plane's shader tree to SHADERS PLUS --> Selective Lighting
Uncheck "Allow GI"
That's it. The shader will now not be effected by any global illumination settings.
I tried that. It does't work.
If you have an infinite plane in the scene with a basic green color shader and you light the scene with an HDRI image that throws a red tint over the entire scene, the green becomes tinted by the red light of the HDRI. Doing what you said to do does not stop the green shader on the plane (and the plane object itself) from being affected (tinted) by the red color of the HDRI. I'm assuming that's what was supposed to happen as that's what the original poster asked for but it doesn't seem to work. Can you provide screen shots?
While were at it can you demonstrate successful usage of the GI shadow catcher feature? I couldn't get that one to work reliably at all.
FYI…
I'm using the demo version of ShadersPlus. I would gladly shell out the $25.00 for the plug in but so far I haven't seen it work properly.
Thanks!
They can both do it.
Change the plane's shader tree to SHADERS PLUS --> Selective Lighting
Uncheck "Allow GI"
That's it. The shader will now not be effected by any global illumination settings.
I tried that. It does't work.
If you have an infinite plane in the scene with a basic green color shader and you light the scene with an HDRI image that throws a red tint over the entire scene, the green becomes tinted by the red light of the HDRI. Doing what you said to do does not stop the green shader on the plane (and the plane object itself) from being affected (tinted) by the red color of the HDRI. I'm assuming that's what was supposed to happen as that's what the original poster asked for but it doesn't seem to work. Can you provide screen shots?
While were at it can you demonstrate successful usage of the GI shadow catcher feature? I couldn't get that one to work reliably at all.
FYI…
I'm using the demo version of ShadersPlus. I would gladly shell out the $25.00 for the plug in but so far I haven't seen it work properly.
Thanks!
You are correct, Selective Lighting does not turn of the Skylight.
(I will contact DCG Eric to let him know. Seems to be a bug.)
Use Lighting Control instead. it worked for me as shown:
If he is using it as a virtual blue screen then he doesn't really need to have the plane in the scene at all. Instead he should remove the plane and render with an alpha channel.
If he is using it as a virtual blue screen then he doesn't really need to have the plane in the scene at all. Instead he should remove the plane and render with an alpha channel.
There are reasons why someone might need a mask rather than alpha. It depends on the scene and what effect you are trying to achieve. (also codec can be a factor if you are not able to use uncompressed or alpha codecs in your edit program.
A quick irradiance map saving way to exclude objects from GI lighting.
Make the object(or plane) invisible. In the render room, use the Irradiance Map: feature(Pro only) to save a map. Now make the object visible again and render loading with the saved map.
To save/load an irradiance map(Sky Light or Indirect Light checked);
1.Check 'Save irradiance Map:'.
2.Click the button(...) below it to name a file to save.
3.Now render your scene once and it will save the map to that file.
----
4.Then uncheck the 'Save irradiance Map:' and check 'Use saved Map:'.
5.Click the button(...) below that and locate the map file you saved.
If you're using a blue screen or green screen when shooting film or video it's because you want to be able to key that color out in post and replace it with something else. They do it that way because in the physical world you can't simply render your background invisible. In the 3D world you can. You do it by using an alpha channel. There is no reason to add a blue or green screen in a rendering only to key it out later.
:roll: Dude, I've had to do it a few times. Why are you making an issue about this?
I'll give you an example.
I needed a mouth with teeth (and a tongue) so it could mouth words, but I wanted only the lips and none of the skin (or interior of the mouth). If you have ever tried to make Vicky's head invisible and leave the teeth and lips you know it is not going to work "just using alpha" unless you want a medical freakshow animation.
Here is a screengrab how it looked in the final video. I needed alpha in the final graphic because of the way I wanted to use the mouth element (objects had to come out of the mouth which were rendered separately, also with alpha). I had to use the Mask shader in SHADERS PLUS to render the skin and innermouth green, then I chromakeyed those parts out in After Effects. As I recall, I actually used Mask to make the mouth interior green and the face skin blue, so I would have the option of chromakeying in stages, with separate masks for inner and outer mouth. That's not how I ended up keying it, but I had the option of defining ANY PART as a Mask. That is what the plugin is for, and why it is called "Mask".
Now please lecture someone else. Sometimes people DO STUFF and they have REASONS for doing it. You can take MY word, or you can keep pedantically denying because you have not yet experienced that need, but I am telling you quite honestly it has to be done sometimes....