adding an external rectangular light (?)

[dcauldwell_cg]

As I sit here waiting for my render, I was wondering if anybody still adds a rectangular light (invisible) on the outside of a window in order to increase the internal lighting level?
I sometime find, particularly with rooflights (Velux), that the light levels don't match the intensity you might expect, when you just rely on GI.

[andybot_cg]

I use a dome light with high subdivisions now for adding GI. (using 100 or more for subdivs.) Gives great smooth lighting from windows. (hsph subdivs in the irrmap have to be fairly high too.)

I used to use just the GI slot, but they've changed it so that you have to have the sun in the environment tab to use the sun, just checking "default lights" doesn't bring up the sun any more.

[dcauldwell_cg]

Thanks Andy, I must experiment with the dome light. Funny how you just get used to doing things in one way.

[dcauldwell_cg]

OK, so far so good. Domelight is working fine.
However, I don't want to use a HDRI image in the domelight, just the sun. Is it possible to have the sun (with shadows) without using HDRI for the lighting in the domelight?

[dcauldwell_cg]

Couldn't get the sun to work with the domelight, so I've used a HDRI image in the domelight and now getting good results with soft shadows.

[andybot_cg]

I use the sun as the GI material in the environment tab in the options (basically what you would have if you load the defaults.) For domelight, I use it without a texture, just a light blue color.

[dcauldwell_cg]

Thanks Andy. I've actually gone full circle now! Back with my original settings with sun in the environment tab (gives better control over direction etc.), but just using the domelight to replace the rectangular light that I had outside the roof window. It is rendering a lot faster now I'm not using the HDRI to illuminate the scene (44 minutes down to 18 minutes)
All working fine now, thanks.
Here is the latest render. Still got to tweak a few things, but nearly there.

[andybot_cg]

excellent! Lighting looks good in your shot. How does the render look without the domelight, I'm curious.

[dcauldwell_cg]

I had tweaked the model a little so I re-rendered for comparison, the first without the domelight and the second with the domelight.
You can see the difference, with the first one being harsher (and colder).

[ValeroStudio]

Not sure if folks still use the rectangular lights on the outside. I used to put them inside so they didn't have to pass through the glass layer. My typical settings for interiors is to just use a very light pale blue color for GI, set to a high number like 25, then add IES lights in the scene. This usually is enough. If I need to see a direct light cast in through the windows, then I use the VRay Sun in he GI slot.

I guess you could always use both the dome light and the VRay Sun set in the GI. Might play with this as I have still not used Dome Light as much as I thought I would. I was playing with it a little today. Found this nice little utility to download full, hi-res Google Street views as a pano. I was plyaing with using it for my dome and it seemed to work nicely. It's not as nice as an HDR file, but you can now grab a full 360 of your site for your projects... until Google blocks this application from working that is.

http://www.purebasic.fr/english/view...p?f=27&t=50248

[andybot_cg]

Matt - the problem with the GI as a value without the sun in the "M" slot is that the sun is not in the scene any more. They changed (as of about service pack 2) the "default lights" override so that the sun is no longer used if it's not in the GI slot. That's why I now use dome light for GI.