Interiors

sheedee3D

Please some professional help...

So far i have been using HDRI (global illumination) to light up my exterior scenes in Iray...now i want to start rendering interiors...but i have no idea how to light interiors...mostly when an interior is totally closed like this one for example:

http://www.renderosity.com/mod/bcs/index.php?ViewProduct=86489

 

i have heard of some people using mesh lights for this purpose...but i have no idea how to use these...

 

any tutorial anywhere on lighting interiors in Iray?...

 

thx in advance.

 

 

Tobor

If the set is closed, an HDR dome will show light only coming through the window. In Iray, environment lights do not penetrate walls and ceilings. So, all the light needs to come from scene lights you place there manually, or natually through the window, as shown in the example. Frankly, it's a great look, and adds realism. It's worth fiddling to get it to work.

One way to replicate this look is to use an Environment dome but no HDR image. Crank up Environment Intensity to whatever level you need to duplicate the streaming light look. If you want a non-specific whitish background, instead of the default transparency, place a white plane primitive  outside thre window, far enough away so that it won't cast a shadow. Or you can add an exterior in post, or use the Background image applied with the D|S Window->Panes->Environment tab (not the same as the Iray Envcironment tab under Render -- yeah, it's confusing).

Another technique is to use a large plane primitive with the Iray Emission shader applied -- that's a mesh light -- but this will increase render times. For a plane that large, the increase in render time could be significant.

Sisca

Another simple way to use sunlight into the window in IRay is to set the Environment Mode to Sun-Sky Only and then adjust the sun position to fit your scene. This should give you light streaming into any windows and just a plain white background like you see in the promos for that set.

If you're trying to light a scene without external openings that would allow HDR or Sun-Sky lighting in I like to use the actual lights in the scene, just apply the IRay emission shader to one of the surfaces and adjust the intensity settings to make it work. For me it's a lot of trial and error to get the right settings for the intensity and color right now, though I tend to set the Luminence Units to Watts and work from there since I know about what a 60W light bulb should look like.

This image (http://aminn.deviantart.com/art/Computer-Room-551139276) over on my DeviantArt page is lit completely by applying the Emissive shader to the various LED's, the bulbs for the overhead lights and the LCD Screen panels. I also applied the shader to a section of the door frame to give the red glow around the door. Using that system it probably took me about 15 minutes to setup all of the lighting vs the hours I've spent doing similar stuff using individual point lights for 3Delight.

 

BeeMKay

I made some test renders a while ago for closed rooms, using different lights etc. Maybe it is of use for you.

http://www.daz3d.com/forums/discussion/comment/869789/#Comment_869789

mjc1016

Sisca said:

 Using that system it probably took me about 15 minutes to setup all of the lighting vs the hours I've spent doing similar stuff using individual point lights for 3Delight.

 

That's definitely the slow way of doing it...there are emissive surface shaders for 3DL (UberAreaLight) that do the same thing as the emissive Iray shader...

But in either case, emissive surfaces are slower to render and need to absolutely have uniform normals in a sane, easily controlable direction.