In the process of particle deposition and stacking (overlapping), particles can penetrate each other (overlapping), or they can only be sticky or binding (stacking). Under the constraints of gravity, buoyancy and viscosity, randomly generated particles will stack into various ever-changing shapes. Sometimes, the unpredictability of shapes is just the need for the richness of mountain and stone shapes. Figure 2 shows several potential movements and tectonic trends generated during particle deposition figure and stacking under the constraints of gravity and viscosity. When rendering, the ever-changing rendering effect is generated due to the different particle sizes, transparency, stacking (or overlapping) density, and boundary fusion degree. Figure 3 is a set of the left, middle, and right rock modeling views based on 3D particle stacking (overlapping) technology built by the author.