This page contains examples illustrating the use of Image-based lighting with V-Ray Dome Light.
Example: IBL (Image-Based Lighting)
V-Ray uses importance sampling to trace more rays in the directions where most of the light is coming from. This ensures speed and quality that were never before possible with pure gathering GI methods.
- Easy setup for image-based lighting (IBL).
- Importance sampling of the dome texture for fast and clean results.
- Support for photon mapping for fast and accurate caustic effects.
In the following example, we show how this works with an HDR image. You can reposition the texture by enabling the Lock texture to icon option in the Dome light rollout and rotating the Dome light. The background is set up as a V-Ray Bitmap Texture.
Initial position of the Dome light. Z axis is perpendicular to the ground plane.
Dome icon is rotated along its Z axis by 90 degrees, causing a different part of the HDR texture to show in the rendering.
Dome light icon rotated by 90 degrees along X axis.
Now we are going to show how the HDRI parameters also can affect the rendered image. We rotate the HDRI from within the 3ds Max Material Editor.
Rotating the HDRI to -200 degrees.
This time we reduce the HDRI multiplier. Notice how the multiplier affects the overall scene lighting. We haven't changed the dome position.
Adding 50 degrees vertical rotation to the HDRI. See how the light and shadows have changed a lot. The highlight position is different now.
Example: IBL and Caustics
Activate the Caustics from the VRay Caustics rollout in the GI menu.
We are using an HDRI with -100 horizontal rotation.
The caustic effect is almost not visible. We raise the Multiplier to 30.0
Rendered image. Now the effect is visible, though the light's caustic subdivisions appear to be few.
Under the Render Setup > Settings > System rollout (Advanced), open the Lights Settings.
Increase the light's Caustic subdivs from 1500 to 15000
Rendered image. Now the effect appears to be clearer.
Set the Caustics multiplier to 30.0, the Search distance to 5.0 units, and the Max density to 0.2cm.