Dynamically work with a very large number of objects/meshes in unity

Question:

I want to render a large number (>10.000) of similar (but not completely identical) objects. In addition, I would like to be able to color and move the objects individually. These objects are currently cylinders with different amount of vertices/triangles.

My Questions for the Experts here is what would be the most effcient way of rendering and interacting with that many objects.

What i tried/thought of:

CombineInstance

What i have done so far is created a MeshManager class which takes each individual mesh and combines them with CombineInstance to a whole new mesh. If there are too many vertices a second, third,.. CombineInstance is created. The class nows in which combined mesh which individual mesh (and the corresponding vertices) is stored. The Problem is if i now want to color each mesh i color the corresponding vertice.

Example:
This is done for each Mesh (i.e. 10.000 Times)

Color[] newColor = mesh.colors;

// Run through all vertices of mesh
for (int vertexID = indexRange[0]; vertexID <= indexRange[1]; vertexID++)
{
    newColor[vertexID] = color[0];
}

mesh.SetColors(newColor);

This is really slow for many objects with many vertices! Especially the mesh.colors call seems to be slow.

Individual GameObjects

Much faster to color and move but no batch effect which means many draw calls. I have then below 30 FPS which makes it not feasible.

GPU instancing

As i can not ensure that i have the same exactly the same object (vertices/triangles) the DrawMeshInstanced and DrawMeshInstancedIndirect Methods can not be used. So Compute Shaders are not an option

As i want to run this on the Hololens performance is important. Did i miss something? Are there any Unity tricks?

The Entity-Component-System is being developed by Unity for the very use case that you describe. It is quite the rabbit hole to go down into, though it might ultimately be what you are looking for.

> An Entity Component System (ECS) architecture separates identity (entities), data (components), and behavior (systems). The architecture focuses on the data. Systems read streams of component data, and then transform the data from an input state to an output state, which entities then index.

Examples for rendering as a use case can be found here and here, for instance.