Daylight Portal

Daylight Portals

a special transparent face placed over an exterior opening or window which causes exterior light to be processed better.

The left half image on the left has a normal (non-Daylight Portal) opening. It took hundreds of passes to resolve properly. The right half has openings marked as Daylight Portals. The lighting looked this good after just a few passes.

Daylight effect through windows.

A Daylight Portal is a special transparent face placed over an exterior opening or window which causes exterior light to be processed better. In IRender nXt, Daylight is a set using the Material Wizard


Daylight Tips

Use accurate values for your lights, daylight settings, and window glass if possible. Because the sun and sky are very much brighter than most lights, you may not see a lot of effect from adding artificial lighting to your daylit scene. This is normal.

Avoid the temptation to artificially boost the power of your light sources. It is legitimate to turn the sun and sky down somewhat, as these are based on a clear, unimpeded sky.

A multi-channel rendering may help you get the picture you want, while still preserving accurate data. See: Lighting Channels

Sky only

This image was rendered for just 1 pass with ordinary openings on the left and Daylight Portals used on the right. You can see that the light coming in through the daylight portal is effective starting with the first pass.


This is the same drawing after just 63 rendering pass. (The improved lighting after the first pass is also a result of Indirect Lighting which adds the effect of light reflecting off of other surfaces during multiple passes.

It would take hundreds of passes for the ordinary opening to process the light from the sky properly.



The images above were made with no sun shining into the window. This image had sunlight, as well as sky and cloudiness.

After 5 passes, the Daylight Portal(on the right) is working fairly well)


Here is the result after 2900 passes. (After lots of passes, the non-daylight-portal opening on the left converges to match the daylight-portal openings on the right.

The Daylight Portal on the right has improved as well, but mostly because of the Indirect Lighting effect.


Setting up a Daylight Portal


Daylight Portals can be set using the Material Wizard to assign the property to a material, or using Object Properties .

Material Wizard

  1. Place a transparent Material in, or behind the opening.
  2. Load the Material Wizard
  3. Click More to load the IRender nXt settings.
  4. Check Daylight from the Transparency section.

Object Properties

  1. Right click on window.
  2. Select Object Properties
  3. Check Daylight

See also