High-quality 3D model of coronavirus as well as its inner modelAdapted only for VrayThe scene contains the virus itself, underneath the parts (meshes) of which it consists(they cannot be deleted because the whole virus is built from these parts. By replacing the material on one of these meshes, the material in the layer that consists of this mesh will be replaced)There are also 12 controllers in the scene. VrayInstancer is a controller that takes the multiplied particles and replaces them with one or more meshes that I wrote about above.(In fact, you only need to touch this if you want to change the geometry to some other. There are 2 fields for this - source - these are objects that will replace particles, and Particles - this box selects the particle system that is used to position the meshes.)And the main controllers are red squares with arrows - these are particle spawners. They can specify fewer or more particles for a denser geometry, or less dense.

A multi-material is thrown over the shell - you cannot drop it, because in addition to the shell material, there are several materials with masks for particles.Therefore, if for some reason it is required to change the shell material, simply replace the material with ID 1 (VIRION) in the multimaterialThat's probably all.