Architectural Visualization with HDRI Skies and Vray by Paco Morales, Mexico

Direct Light Setup



We create a direct light with the values shown in the image shown to the right. You can follow the images to see where I have placed the light. But this is a matter of taste, and of course, it depends on the particular scene.


Press (Alt+B) and a win­dow will appear (Viewport background). Use the values as shown on the screenshot. Then adjust the direct light as per the image above, because we need to match the direct light with the sun position within the HDRI.


Shadows

Here is the image with the direct light; this provides strong but dispersed shadows. In the images shown to the right, different values have been applied to the V-Ray shadows with resulting levels of shadow sharpness.

The first image has a value of zero (0 with 32 subdivi­sions), giving it a focused look with no fading. In the second we have a value of 1 (1 with 32 subdivisions), and there is now some fading in the shadow borders. And so on till 4 with subdivisions. I personally use a value of 3.0 with 32 subdivisions most of the time.


Exposure

Here we have the image with pure illumina­tion provided by the HDRI, without direct light and the resulting soft shadows. De­pending on what size lighting HDRI you use, and whether you blur it or not, you will find that you can achieve anything from very blurry shadows to quite sharp. However the larger your lighting HDRI, the longer your render times and the harder it will be to remove speckling/splotching artifacts.

Depending on the scene and the look we wish to achieve, we can work with or with­out direct lights. For example in this cloudy sky image, the sun is behind the clouds, giving a soft shadow look. Many of the HDRI Skies in the Hyperfocal range have the sun positioned on a cloud edge, allowing the artist to choose a direct light/hard edged shadow appearance, or a soft shadow ap­pearance as if the sun is behind the clouds.