Lights visible (and unwelcome) in ALL of my render passes

Support Lighting and Rendering
#1

I’m rendering a scene with a mesh light and a directional light.

I’m trying to break up my render into two lighting passes, one with the mesh light, and one with the directional light.
My geometry is on layers 1 and 2.
The mesh light is on layer 1.
The spot light is on layer 2.

I have two render passes one that includes only layer 1, and the other that includes only layer 2.

My problem:
Both lights are appearing in both passes. Why?
How can I fix this?

Attached is my .blend file.

LightPasses.blend (533 KB)

#2

You’ll need geometry on all layers, and then set the lights to “this layer only”.

#3

Where do I set it to “this layer only”? I can’t find it in the properties panel.

Why do I need my geometry on all layers if I include the geometry layer in all the passes?

#4

Make 2 layers each with all the geometry, except one with the mesh light, and one with the directional light.
It appears that it may be a bug doing it the way your doing it.

#5

That doesn’t work.
I’m getting both lights in both passes.
I’ll post my .blend file.

#6

Yeah, I think there is a bug.
As a work around, you could just render 2 separate images and export each in open .exr format. Then import those into the compositor.

#7

True.

I noticed that I can remove lights from a pass if I toggle the “exclude” buttons.
So … I’m wondering, why is there an “exclude” option? What’s the point in having a panel of buttons that include layers and one that excludes them? Isn’t that redundant?
Is there some functionality in there that I’m not understanding? Is it causing my lighting problem?

#8

I’m wondering the same thing.

#9

Exclude layers are good. You could use them to render a 2 packshots that are on the same position. So you can render one pack and exclude the other one. So packs (or objects) dont interfear and are rendered seperately in one render take.

#10

Why would I do it with the “exclude” buttons instead of just picking the desired “layers” buttons?

#11

Let say you have 2 cubes at the same spot on red and one blue and a background. And you want to render it in one take.

  1. cube layer one (exclude lay 2 and 3)
  2. cube layer two (exclude lay 1. and 3)
  3. background plane layer three (exclude lay 1 and 2)

Than open node editor and set three render windows and three outputs. And with this exclusion we can render whole anymation and layers without needing to rerender every cube on its own.

Hope it helps.

Try to render 2 cubes on the same spot in one go…every cube in its own render…

Take care

#12

There are multiple solutions. But in this case…
layer 1 - geometri
layer 2 - mesh light
layer 3 - spot light

So if you want to render in one go and get two renders of same geometry with different lights.
U set one render layer to render:
lay 1 and 2 than exclude lay 3

And second render layer to render:
lay 1 and 3 than exclude 2

Set output in node widow select all three layers and RENDER :smiley:

Take care

#13

Oh ok, so instead of rendering one render layer at a time, you can have them all render at once with the exclude buttons. I think I get what they are for now. Thanks Vandorious!

#14

I think I understand what you’re saying, but I don’t understand how this is different to

  1. Render only layer 1
  2. Render only layer 2
  3. Render only layer 3
    ?

Thanks

#15

Because you have to manually start the render every time you switch the layers that are to be rendered.

#16

The answer may be…
Lets say we have 2 cubes a character and a light. Character casts a shadow over cubes. We need to render in one go and separate all three objects in each rendered image. Cubes must not “interact” in render but we must catch the shadows on both cubes. Character should “interact” with cubes so we get AO, light scatter etc. on the character.

So we set the scene…

  1. layer: red cube
  2. layer: blue cube
  3. layer: character
  4. layer: light

Than render layers…

first rend layer (red cube with char shadows): lay 1 and 4, exclude lay 2
second rend layer (blue cube with char shadows): lay 2 and 4, exclude lay 1
third rend layer (character): lay 3 and 4

Select layer 1, 2, 3 and 4. And render.

So in this case we didnt exclude character layer to get the shadows in box render layers. And we didnt exclude cubes in character render so the character and cubes render together but the cubes themselves arent visible.

#17

Are you saying that the character will cast shadows even though layer 3 is not selected in the first two passes?

#18

Yes! If u select all 4 scene layers at render!

#19

Awesome!
I get it now!
Thank you!