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Jennifer

Physical Sky with HDRi reflections?

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Hey guys, 

 

I rarely use Physical Sky to illuminate my scene, mostly Sky+HDRI combo. But this time I need real daylight, hard shadows and I don't know how to do it with HDRi. So I bring up the Physical Sky, but now all my realistic reflections are gone, leaving me with plastic, flat looking render. 

 

Is there a workaround to this?

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  • 1 hour ago, danijelk said:

    Hi,

     

    Use some high contrast clear sun hdri map, to get harder sun shadows, you can find them here https://hdrihaven.com/hdris/category/?c=high contrast&o=popular

     

    Cheers, Dane

    Thanks, so using Phys Sky won't allow me to enable realistic reflections, right?

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    1 hour ago, Jennifer said:

    enable realistic reflections, right?

    lolcats 🙂

    The realism of reflections comes entirely from the detail and contrast in whatever you are using for a sky. The default physical sky is not very detailed at all, so if you want to use that for refs, then you have to make it so using the numerous sky controls. There's a weekend gone right there 😉 !

    The real advantage of the Physical Sky is its sun controls and the fact that you can easily move to any time of the day or night and get a reasonable start to your directional and ambient lighting.

     

    In your case though, and where you want a nice quick easy result, then either do what Dani said, or use any old HDRI with proper dedicated sunlight as well, which Cinema offers via it's sunlight or directional light types. Even though sunlight produces quite a hard shadow, it is still best to use area shadows on these lights (as opposed to raytraced or shadow maps), which are more realistic.

     

    CBR

     

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  • 4 hours ago, Cerbera said:

    lolcats 🙂

    The realism of reflections comes entirely from the detail and contrast in whatever you are using for a sky. The default physical sky is not very detailed at all, so if you want to use that for refs, then you have to make it so using the numerous sky controls. There's a weekend gone right there 😉 !

    The real advantage of the Physical Sky is its sun controls and the fact that you can easily move to any time of the day or night and get a reasonable start to your directional and ambient lighting.

     

    In your case though, and where you want a nice quick easy result, then either do what Dani said, or use any old HDRI with proper dedicated sunlight as well, which Cinema offers via it's sunlight or directional light types. Even though sunlight produces quite a hard shadow, it is still best to use area shadows on these lights (as opposed to raytraced or shadow maps), which are more realistic.

     

    CBR

     

    Gotcha! So the ultimate combo would be an HDRI sky with stock Sunlight. Is it not possible to use physical sky's sun and just disable the actual sky? Sorry for the tautology. 

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    6 minutes ago, Jennifer said:

    Is it not possible to use physical sky's sun and just disable the actual sky? Sorry for the tautology. 

     

    Yes, and that will leave you with just the sunlight. To do that just go to the basic tab of Phys Sky and turn off sky there. Obviously you will lose any nice ambient light coming from that sky (after all the outside is not lit by sun alone), but it may be what you want...

     

    Recognize what is going on here though. HDRIs are used for both reflection AND illumination (if GI is turned on). Physical sky tends to look a lot more realistic with GI on for example (there's even a dedicated GI preset for it !)...

     

    So, if you ARE using GI, and want your lighting to come from the HDRI AND the sun, then that's what you do. No GI means you are only getting reflections from the HDRI and the only lighting in your scene is coming from the sunlight, which probably means you need another light source in there to simulate ambient or 'sky-dome' light, which is what the Physical Sky's Sky Tab would have provided if you'd left it on ! Make sense ?

     

    CBR

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  • 26 minutes ago, Cerbera said:

     

    Yes, and that will leave you with just the sunlight. To do that just go to the basic tab of Phys Sky and turn off sky there. Obviously you will lose any nice ambient light coming from that sky (after all the outside is not lit by sun alone), but it may be what you want...

     

    Recognize what is going on here though. HDRIs are used for both reflection AND illumination (if GI is turned on). Physical sky tends to look a lot more realistic with GI on for example (there's even a dedicated GI preset for it !)...

     

    So, if you ARE using GI, and want your lighting to come from the HDRI AND the sun, then that's what you do. No GI means you are only getting reflections from the HDRI and the only lighting in your scene is coming from the sunlight, which probably means you need another light source in there to simulate ambient or 'sky-dome' light, which is what the Physical Sky's Sky Tab would have provided if you'd left it on ! Make sense ?

     

    CBR

    Totally. Quite an expert you are! ;))

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