Help for my confusion about Render Setting Environment Mode

xix_81148dd33e

Hi, hellow from Japan.

I am confused becouse the Iray rendering results are

  more bright (Render Setting : Environment Mode = Dome Only),

  more dark (Render Setting : Environment Mode = Dome and Scene),

even though same scene, same camera.

My understanding is that

 more dark(Render Setting : Environment Mode = Dome Only),

  more bright (Render Setting : Environment Mode = Dome and Scene).

The scene includes some spot lights.

The camera head lamp is off.

The render setting is Default setting, only Environment Mode is changed.

Spot lights in the scene all off and 

Render Setting  Environment Mode = Dome and Scene

makes more bright.

Adding spot lights make more dark ???

What is my misunderstand ?

I need help.

 

xix_81148dd33e

I add the evidence.

Scene : includes 6 spot lights for the Genesis8 face.

    (scene includs one Genesis8 Female and 6 spot lights )

Camera : Headlamp Mode is off.

Render Setting : Default, Auto Headlamp is Never.

 

1. Render Setting Environment Mode changed to Sean Only.

The result as ...

Her face illuminated by spot lights in the scene, good.

 

2. Same scene, same camera, 

only Render Setting Environment Mode changed to Dome Only.

The result as ..

Her right side shoulder and west illuminated by IBL, good.

 

3. Same scene, same camera, 

only Render Setting Environment Mode changed to Dome and Scene.

The result as ..

Her face looks like more brite as Scene Only case, good.

Her right side shoulder looks like more brite as Dome Only case, good.

But, her right side west looks like more dark than Dome Only case, why?

I can not understand it.

The Dome and Scene case is always bright than Dome only case,

isn't it ?

What is the dark matter in my scene ?

Can anybody tell me why the phenomenon occurs ?

 

Richard Haseltine

I just set up a really simple scene - default Genesis 8 Female with Basic Wear sitting on a cube using one of the default poses, with a 6,000 lumen spotllight shining at her face. I then did three renders - Dome Only, Scene Only, and Dome and Scene. In my image editor I loaded the Dome and Scene one first, then added the other two as layers on top and grouped them. Setting the top layer in the group to Screen blending mode and the group to Difference should give a pure black image, if the two separate renders combine to give an exact match for the render using both light sources, but in fact they don't - adding a levels adjustment layer on top it is clear that there is a noticeable difference around the face and some difference across the whole render. So I agree that they do not combine as I would expect, but I'm not sure why

xix_81148dd33e

I noticed  my misunderstand !

 

I thought lights don't block light.

But it was a misunderstand.

The spot light whose Light Geometory is Disc,

it blocks other light, ie, IBL's light.

'

I want to know the setting not to block light...

 

 

 

Richard Haseltine

Ah, yes - though that wasn't my issue as I left it at a point. Have you tried turning Render Emitter off?

xix_81148dd33e

Thank you for your reply.

And thanks for the verification.

 

For my cace, I think,

6 spot lights in my scene block IBL's light.

So the block make more dark at her west.

The block ocurs with "Dome and Scene", not "Dome Only"

  

xix_81148dd33e

Yes,  I tried Render Emitter off.

But still block light.

 

As far as I know, for remove the block,

Light Geometory changed to "Point".