Snow Accumulation System

Study on hlsl with 2dgrid niagara grid.
The system consist in 2 different niagara emitter: one for the particle, one for the grid2d system; and one BP.

The particle are finite, they live indefinitely, looping it's position. At each start of the cycle the particle initial position is recalculated;
So they remain consistent in their movement and at the end of their cycle they reach the ground.
The float cycle is used in the iteration grid phase to optimize a bit, skipping some computation. ( >~ 0.8 LifeCycle)

In the 2dgrid iteration stage It sample each particle position and check the distance from the particle to projected world grid;
Each distance is then stored in one stackcontext and then wrote in one RT.

The BP is used to store the Depth RT used for the niagara and to draw the stackcontext information from the current RT to the persistent RT.

More detail in the breakdown.

The end result is then projected to the material; I used parallax mapping instead of displacement.

Tree, rocks, mountains assets are from the Marketplace.

Usefull link:
https://www.kodeco.com/5760-creating-snow-trails-in-unreal-engine-4
https://youtu.be/3fW5xjiDm-A?si=Ln4EwDodAWoPa_33