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HDRI illumination on exteriors?


archkre
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And for the end results of an exterior ,the use of that HDRI is noticeable and worth using, because that render would take much longer and more resources intensive than another with a light blue color like sky!

And where do you use HDRI in VRay, in Environment/Ilumination, or refl/refract. or in both?

Thank a lot!

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brian and james , can you show us any of the exteriors done with lighting with hdri exteriors..... i tried doing them with very less joy ....it iwll be much appreciated

 

sorry hadn't checked the thread in a bit.... here's two courtyards I'm working on for a hospital our firm is doing. The daytime shot is lit by an hdri and a vray light (sphere). And the dusk shot is lit only by the hdri.

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heres a link to my latest pieces, they use HDRI and a vray sphere for the direct light

 

http://www.cgarchitect.com/vb/showthread.php?t=16329&page=2

 

 

Daniel, i use the HDRI in both vray's environment and reflection overrides

 

That is a big overkill. If you use the enviroment override for the GI, you sould not have to use the Vray Sphere. You rae basically doubling your enironment (ambient) lighting.

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chris...? I'm a little confused, jat10005 said he used a vray sphere for his direct light, and you're saying that's overkill. I read that as he's doing the same thing your tutorial does (highway scene) to suppliment the hdri with an vray sphere (no decay) to act as the sun for casting shadows.

 

or are you referring to something else when you refer to a vray sphere?

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Chris...you got me all confused now.

 

I just watched that part of the DVD again to verify and indeed you are using both the HDRI for GI and the V-RAY sphere for direct light (i.e. for shadows). I ran an exterior out last night with my HDRI set to mult of 3 and my V-Ray light (sphere) with no decay set to 1.5. I got very nice GI and great direct light with shadows...please enlighten us.

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this is a topic i have been meaning to start anyway...

 

as long as we are on the subject of using a Vray sphere as a sunlight source in combination with a HDRI... what advantage does it offer over using an IES sun with the inesity setting lowered anywhere from 500-1500 in combination with a HDRI sky?

 

i tend to use the the later method.

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chris...? I'm a little confused, jat10005 said he used a vray sphere for his direct light, and you're saying that's overkill. I read that as he's doing the same thing your tutorial does (highway scene) to suppliment the hdri with an vray sphere (no decay) to act as the sun for casting shadows.

or are you referring to something else when you refer to a vray sphere?

Nope... I was the one confused... sorry guys. I thought he was talking about using the Vray DOME light. As you can imagine, using a dome light on top of the HDRI environment would be overkill. I was wrong in thinking that this is what he was doing. Yes... after clearing things up, what he is doing is correct.

 

Sorry... I have been working on a movie for 10 months and I have 3 weeks left... you can imagine my brain is getting a little fried.

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this is a topic i have been meaning to start anyway...

 

as long as we are on the subject of using a Vray sphere as a sunlight source in combination with a HDRI... what advantage does it offer over using an IES sun with the inesity setting lowered anywhere from 500-1500 in combination with a HDRI sky?

 

i tend to use the the later method.

 

BTW... I should point out that there is no "correct" way of doing it. There are many ways to do it. I like using the Vray sphere light and the HDRI because I can control it well and it can get great results. There are many ways to do things, including full blown IBL (no CG light added). So don't beafraid to try your own ways of lighting.

 

I actually have other aesthetic reasons for choosing the Vray light over a directional or IES light.... that is mainly to match lighting that is done in features. Rarely on a set is the sun actually the true sun, but usually a big old 5k or 8k light out there, and the sun is blocked out with a flag. When ever lighting looks really good outside, it is usally because the lighting is done with artifical lights. Sunlight makes it look flatter, has less dimension. Using the Vray Light, you can sorta go half way between the two. It is more of an "artistic" move.

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Christopher: I don't understand how you are gonna get sharp shadows

(sun like) with Vray lights and HDRI!

Those only cast diffuse shadows, or am I wrong?

Thanks

 

Well first off, the sun does not cast sharp shadows. Even the sun is an area which over distances has a slightly soft shadow. All you have to do is look at the shadow of a really tall tree on the ground next to your shadow to realize that its shadow is much softer than your own. So the VrayLight can make that happen. Hazzier days can exagerate that effect, and you can control that with the Vray light by changing its size.

 

Next, the Vray light does not just cast diffuse shadows. It casts reflections (specular) as well. It will ignore the specular if you select it to bake in the shadows with the IR map.

 

Anyway.... buy my DVD... it is all in there. :)

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Excuse me, but what tutorial and DVD are you talking about?

Thanks

Encore question!

And let's say for the case of a house ,how far from the target would you put your Vray-sunlight,how big and how intense( in feet and inches)?

Thanks a lot!

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I second that question please...

 

I know that every situation is differant but as GENERAL rule of thumb how big should we make the sphere, how intense, and how far should it be from the geometry???? Someone with some free time (yeah right) do some tests and post the results please.

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