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diamondjim

Exclude Object from "Blocking" GI

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Hi all,

 

I have a scene lit by a luminant HDRI on a Sky object. However, my scene is "inside" of a warehouse, complete with walls and a ceiling. Therefore, when the warehouse objects are enabled, they "block" the Global Illumination from lighting the objects inside of the warehouse. I've already tried to apply Compositing tags to the warehouse ceiling and walls with "Seen by GI" unchecked, but all that does is refuse lighting from the Sky while still blocking the other objects from receiving the Sky GI. I've also experimented with disabling "Seen by Rays", and while this works for the GI, I lose the reflection properties I want the polished floor to interact with the walls and ceiling of the warehouse.

 

Thanks in advance for your help!

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No, you're doing that wrong. If you are in a an enclosed space it is a terrible idea to try and light the scene with something outside that structure ! There will be lights in that warehouse, and you should be using those to illuminate it... you can still use GI, but the sky is pointless unless part of the warehouse is open.

 

CBR

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  • 18 minutes ago, Cerbera said:

    No, you're doing that wrong. If you are in a an enclosed space it is a terrible idea to try and light the scene with something outside that structure ! There will be lights in that warehouse, and you should be using those to illuminate it... you can still use GI, but the sky is pointless unless part of the warehouse is open.

     

    CBR

     

    I understand it's not a physically-accurate way to get what I want, but I really like the reflections of the sky HDRI image on the objects inside the warehouse. It's a complex vehicle with high gloss paint so you can't make out really what the reflections are anyway, so really what I want is the reflections from the Sky object, less so the GI

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    Oh that's more doable 🙂 In the compositing tag on the warehouse Geo, just turn off 'seen by reflection'.

     

    CBR

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  • 1 hour ago, Cerbera said:

    Oh that's more doable 🙂 In the compositing tag on the warehouse Geo, just turn off 'seen by reflection'.

     

    CBR

     

    Thanks for your help thus far, but I don't think that's quite what I'm after. I want the vehicle in the warehouse to receive GI from the Sky and also its reflections (to see the Sky in the vehicle's paint's reflections). Turning off "Seen by reflections" for the Warehouse itself will just make it so there are no warehouse reflections in the vehicle paint, but it will still be blocking the vehicle from being seen by the Sky. It's like there needs to be an option or tag that I could apply to the Sky object to completely Exclude the warehouse. Maybe a Compositing tag and then add the warehouse geometry to the "Exclusion" tab?

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    OK, well now we're back at my first answer...

     

    8 minutes ago, diamondjim said:

     Maybe a Compositing tag and then add the warehouse geometry to the "Exclusion" tab?

     

    I'd try it and see. I don't know if that will work or not, but suspect the latter. Do let us know !

     

    CBR

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  • 16 hours ago, Cerbera said:

    OK, well now we're back at my first answer...

     

     

    I'd try it and see. I don't know if that will work or not, but suspect the latter. Do let us know !

     

    CBR

     

    yeah unfortunately it didn't work. Ahh well, I'll just do it the right way instead (ugh)

     

    Thanks again for your help!

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