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HDRI illumination on exteriors?


archkre
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I know that every situation is differant but as GENERAL rule of thumb .......

 

I've pretty much learned there's only one GENERAL rule of thumb in architectural CG...... there are no solid rules of thumb!.

 

Train your eyes to experience the real world and then critique what makes your scene different. That should help out your sun placement.... figuring it out yourself will allow you to learn so much more than soemone telling you where to put it. (OMG.... that sounded like a university proffessor statement, someone shoot me)

 

...this is not me trying to give anything away from Chris's dvd's, trust me you still need to get them, you will learn so much more in a few chapters than you could imagine..... things you never thought about, but should!

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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

 

You can choose what kind of shadows you want the light to cast. Isn't it?

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I have some questions about the HDRIs

I was browsing through dosch design library and I got a little confused...

There were some HDRI like "cross" some black ones and some freaky stuff (here is link you will need a Adobe Acrobat Reader Dosch Design)

So my question is when should I use the different types.

All of my knowledge about HDRI and Vray a got from the Chris's DVDs but unfortunately he didn't use the freaky ones so I don't know how to use them. But aside that the DVDs are were very helpfull and helped me to get to the finals of National Informatics Olypiad 2006.

And I also want to ask about that movie he is working on....how is it called...I'd like to see it and perhaps to learn some techniques.

And also...are there any animated HDRIs. I think you can get some cool results from an animated HDRI for sky.

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I have some questions about the HDRIs

I was browsing through dosch design library and I got a little confused...

There were some HDRI like "cross" some black ones and some freaky stuff (here is link you will need a Adobe Acrobat Reader Dosch Design)

So my question is when should I use the different types.

All of my knowledge about HDRI and Vray a got from the Chris's DVDs but unfortunately he didn't use the freaky ones so I don't know how to use them. But aside that the DVDs are were very helpfull and helped me to get to the finals of National Informatics Olypiad 2006.

And I also want to ask about that movie he is working on....how is it called...I'd like to see it and perhaps to learn some techniques.

And also...are there any animated HDRIs. I think you can get some cool results from an animated HDRI for sky.

 

The cross is just another way of doing the environment map. The cross is often refered to as a cubic map (6 sides of a cube). The one I use is called a Lat/long map (or spherical). Either way it will work as long as you switch your VrayHDRIMap reader to do Cubic or Spherical.

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The cross is just another way of doing the environment map. The cross is often refered to as a cubic map (6 sides of a cube). The one I use is called a Lat/long map (or spherical). Either way it will work as long as you switch your VrayHDRIMap reader to do Cubic or Spherical.

 

Please, Christopher tell me how far, how intense and how to deal with the shadows of the Vraylight spherical acting as Sun!

I promess I am gonna buy your Gnomon CD ASAP, when I can save $59

plus shipping & handling!

Thank you very much!

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there really is no straight answer to your question.... they'res too many variables. For instance, what time of day, what month is it (sun direction), whats the scene material, is it all snow?? is it all black mulch (hmm not sure that exists).... anyways, other influences, what are the imbedded intesity values for your hdri, this varies between different hdr's obviously. How big is the diameter on your vray light (hint...hint)... and what is it's intensity?

 

pretty much you need to just start playing with your values till you find something that fits your scene. Now Chris's DVDs will give you a good eye towards what you need to focus on, but thats more of something you need to hear see and exprience not something that could be dropped into a thread without composing a novel.

 

the best thing for you to do would be to setup your scene, play with it, and start posting in the WIP forum and try to get some comments to help you improve your scene... that way you get your answer.... and learn why you need to change it....

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I don't have vray here, but I think there's a rollout in the vray light, that allows you to choose what kind of shadow. I can't check it here, though!

 

However, with HDRI you can't do anything with shadows, you're right.

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Thank you Brian... well said. Remember we are artists not mechanics.

Well, it is the old controversy about us, Architects ! Are we artists or technicians?

I think we are a much more complex combo: Artists, technicians, paralegals, accountants, engeneers, mechanics, salesmen.....!

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Dear Mr. Nichols: After having watched your very interesting

video on Vray-Exteriors, some questions arise:

*Why do you always use QMC as secondary (which is a

brute force method) and not Light Cache e.g.?

*When you use that illumination card for the interior of that

structure to receive light, why don't you simple increase the

light absorbing properties of those dark zones?

*In the same scene you use a 30M diameter "sun", if we

work in feet/inches, should we use the conversion factor and

have a 90 feet diam. sun ?

I presume that the intensity remains the same.

In the scene of the dominoes, I notice the intensity of the sun climbs to 600!! Why?

*How do you use HDRI's in the environment section , but this time for reflexions?

* When to use exponential and when HDSexponential exposure?

Thanks a lot for your great help!

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  • 2 years later...

Hi Guys! nice discussion!

i have one question, i've been trying now for weeks to find the best settings for a combination of vraysun and hdri with no luck, it can(i believe) produce good results. i used a sphere and assigned a vraymaterial to it, with hdri as map.so i want to know if anyone of has tried this before. thanks!

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