For creating dappled light in 3ds Max (2018–2023), the most widely recommended specialized tool is the Dappled Light Generator by ArchvizTools. Top Choice: Dappled Light Generator (v1.0 - v2.0)
If you are still on 3ds Max 2018, you cannot use OSL shaders natively. Instead, use the VRayDirt in "Ambient Occlusion" mode inverted, plugged into a light’s Gobo slot. It’s clunky, but it works. dappled light generator for 3ds max 20182023 f better
The proposed tool operates as a Parametric Modifier (DappleMod) and a Helper Object (DappleGrid). It utilizes procedural noise algorithms and projection mapping to simulate foliage shadows without the need for heavy source geometry. For creating dappled light in 3ds Max (2018–2023)