This video goes through the steps to creating an animated clipping plane within VRay for Grasshopper using Rhino 8. It is recommended that you first watch the VRay for Grasshopper Setup video before following these to understand the initial setup required for creating a VRay render within Grasshopper, linked here:
https://youtu.be/B9CxefOgeoU
The key steps in this video can be found below:
00:00 - Introduction
01:30 - 'VRay Clipper' node
02:20 - Creating and adding the clipping geometry
04:50 - Using Grasshopper to move the clipping plane
06:58 - Animating the clipping plane using the 'Timeline' node
10:25 - Changing the colour of the section cut
11:38 - Rendering out the final animation