this tutorial will teach you about basic simulation nodes in blender and how to use them to setup a melting effect, you can use this setup to melt any meshes by moving a melter object close to the object and by proximity that mesh area will be will melt.

you can explore the project files here

patreon ,Gumroad ,BlenderMaket

how to setup a melting object simulation

Melting mesh

Add a geometry nodes setup to the mesh, and add a simulation zone, connect the nodes like in the image.

the simulation zone works like a loops that runs every second, for example the set position in this setup will add an offset in the z direction of 0.1 every frame on the connected geometry, which will animate the geometry moving up, you can substitute this node with different nodes or other nodes setups, as long as there in the simulation zone, the effect the produce in one flame will be compounded on in the next frame as the loop runs.

the screenshot above shows the geometry nodes setups for the melting effect, as you can see, its fairly simple, this is all based on the set position node, that will change the position of the geometry by the offset you set, because the position node is withing the simulation zone, the offset is added at every frame creating an animation.

Need blender crowds in your scene?

for the melting effect, the offset is an noise texture in the z direction, thats why i added a combine xyz node to separate the xyz components so that the noise only affects the z direction. the noise scale is going to be the scale of the melting parts, i added a scale vector node to control the scale of the noise, if this is fed directly into the set position node the mesh will be displaced in the Z axis and will move down.

To get the proximity mask so as to only melt the objects close to the sphere, a uV sphere object is added and imported into the node setup with the object info node.

a proximity node is used to get the distance between the sphere and the geometry, that distance is used to scale the noise so that only the close vertices are melted.

the mesh to volume and distribute points in volume node are there to make sure the sphere has points inside itself, otherwise the proximity mask will be for the shell of the sphere and the melting will not work right.