In this tutorial you can learn how how to set up and light a sketchup exterior scene with a HDRI Skydome and Vray. While HDRI lighting is simple, there are a few things that might help you get better results.
The VP HDRI Skydomes have a very high dynamic range, which is best to create sharp sun shadows. Also, they have an accurate white balance that will bring convincing and colorful lighting into your scene with a few clicks.
Basically, you just need to follow 2 main steps : First to load the hdri skydome you want to use, and second to adjust camera settings such as exposure and white balance.
(1) Load and adjust the HDRI file
First create a dome light and open the light editor. In the panel Dome Settings add a texture in the slot “Dome Texture“.
Set it as texBitmap and load your HDRI file.
At the bottom in the UVW panel, set the UVW type as UVWGenEnvironment and the mapping type as Spherical. In the UVW panel you can change the horizontal rotation from 0 to 360 degrees in order to rotate the sky.
If you want to get sharper shadows you can change the gamma value. Values that usually work good range from 0.75 to 1.
Until this point we have added the skydome to our scene and loaded the skydome file.
In the next point we will treat the camera settings. Before we move onto the next point, letís speak about the gamma setting.
This setting allows colors to have more punch and contrast, in an high dynamic range context it means that bright spots are much brighter than normal, therefore creating sharper and stronger shadows.You can increase this value if you feel the light is a bit too flat to bring more contrasts, or decrease it if the light gets too harsh.
(2) Camera Settings
There are basically two things we want to achieve when setting up the camera: a proper exposure, and an adequate white balance.
To set this up you need to go to the Camera settings tab of the Vray render options window.
The most important settings are shutter speed, F-number and white balance. To increase the exposure you can decrease the shutter speed and/or the F-number.
Using one or the other will depend on motion blur or depth of field effects you want to achieve.
Ultimately you can use the ISO, the higher the value, the brighter the picture. Common values range between 50 and 1600.
Also, sometimes having white areas looking blueish or reddish can lead to a better overall result and is dependant on the mood you try to achieve.
Finally, the white balance setup helps you adjusting color values. The best way to set it up is to pick the color from the part of your render you want to be white. Also, sometimes having white areas looking blueish or reddish can lead to a better overall result and is dependant on the mood you try to achieve !
All of the VP HDRI Skydomes include sketchup scenes with proper light and camera settings, so you can just go ahead and start rendering your own scene.