HDRI Newbie, to use it or not to use it?

[ivanjay]

Hey all.

 

I work with Max Design 2010 (mental ray) and create interior visualizations of foodservice spaces (cafeteria's, restaurants, etc.)

 

Often the spaces work with have windows and I typically place an environment map of the sky to give a visual out the window. However, when I place a daylight system in there it sometimes gets too bright and I can't see out the window anymore.

 

My question is to HDRI. I see a lot about it. Is there any benefit to using HDRI in the types of renderings I described above or is it just unneccessary? Attached is a sample of a recent rendering to give you an idea. The bright white in the background are the windows....

 

Thanks all

 

-Ivan

[padre.ayuso]

Hi Ivan,

Your image does seem blown out from the windows. However, I do not know much about HDRI and working with them. What I use is an alpha channel and in PS I paste it in and do any photoshop I need to the environment. This works for me, that way, even if the client decides to change the environment because he does not like it or whatever, you can do it in less than 5 minutes in Photoshop! Hope that helps!

[Justin Hunt]

Its also a question of how much you want to be physically accurate or artistic in your representations.

 

Physically the windows will be blown out with the exposure you need from the inside to be bright.

 

If you want a more pleasing image then there is nothing stoping you from darkening the backround. One way round is, if you place a MRPortal Light in the window, you can turn down the transparancy to dull the view outside without affecting the light entering the room. The max help files cover this quite nicely

 

jhv

[ivanjay]

Thanks for responding all. I am using gamma 2.2. I tried playing with exposure to get it right but just couldnt get it.

 

I will try darkening / shading the sky portals. That is an interesting idea.

 

I think the largest issue is that this is physically correct, I have a photo from the same angle and that is what you see! The sun glares through this windows as it is southern exposure in ny.

 

However, this is in NYC... The one big difference is there a lot more shade opportunieis because of surrounding buildings. But, I certainly do not want to model the skyline lol

[padre.ayuso]

I think the largest issue is that this is physically correct, I have a photo from the same angle and that is what you see! The sun glares through this windows as it is southern exposure in ny.

 

Someone correct me if I'm wrong, but depending on one's camera settings in the physical world, one can get a glare from the window and so it looks blown out or it can be less blown out, depending on your exposure settings. I'd just play with it until you are happy with your whole thing. On the re-creating the whole skyline... hmmmm, I think it would be a good idea to cheat it! and you would get a more accurate rendering. I have had to do that before and it makes a big difference!

[Playdo]

As Justin Hunt said above, your scene is exposed for the interior which will in turn over expose the daylight coming through the window (as it would with a real photograph).

 

As mentioned, a way around this is to increase the transparency of the sky portal (there's a colour tab in the parameters), allowing your backgound to show.