This addon is bundled with Genie (get it heavily discounted)!

Melt Simulator

Melt Simulator is it's own mini fluid engine built specifically for melting objects! Use any viscosity, activator, and colliders.

The simulator has 3 general modes (useful for different use cases):

1. Particles - the actual particles used in the simulation.
2. Instances - instances small cubes on every point (sometimes necessary for Cycles).
3. Mesh - a 'skin' of the particle system.

There is also (experimental) uv advection! This means you can maintain the original uv/coordinates even during deformation. Works best with a detailed simulation.

Unlike Blender's fluid simulation you can activate sections over time using an activator object:

The simulator uses simulation nodes in the backend so just go to frame 1 and hit play.

Settings

Quality (integer) - Number of substeps in the simulation.
Viscosity (integer) - How much the fluid sticks to itself (think honey or glue).
Drag (integer) - General velocity dampening.
Voxel Size (factor) - Size of the underlying particles. Smaller values are higher resolutions.
Use Activation (boolean) - If enabled will use a custom activator object.
Activator (object) - The object used for activation.
Colliders (collection) - Collection of objects fluid will collide with.
Type (menu) - Switch between using particles, instances, or meshing.
Mesh Scale (float) - Scale multiplier for particles before meshing.
Mesh Blur (integer) - Smoothing of the mesh.
Velocity (float) - A multiplier for the velocity attribute. Mainly for shading but be careful with motion blur.

Tutorial

Installation

Install like any other addon. Drag the .zip right into Blender (4.3 or newer) and click confirm.

That's it!