koobas.hobune.stream
Efficient mesh vertex count changes?
I have a mesh I am constructing in code and I want to dynamically add and remove vertices. Right now it looks to me that to change the vertex count I have to specify a completely new array for the mesh.
Is there any way to avoid this? I am thinking something along the lines of I give mesh an array of indices as well as a length, which is uses instead of the actual array length. So in that case if I had an array of 100 verts capacity I could use only 4 of those verts one time, then 10 verts the next time, etc, without having to every create new arrays and later free them. (I want to avoid dynamic constant dynamic allocation / deallocation)
As far as I know in C# there is no way to have an array point to some shared memory - ArraySegment looked promising but it doesn't really do that. Nor can I subclass array.
Maybe there is some C++ magic that can be done to accomplish this? Again, the key goal is to allocate an array with some capacity and then feed that into mesh for vertices / indices / etc such that the length can be different from the capacity and I don't have to allocate new arrays for each length change.
As a suggestion, declare your vertices array with 100 vertices, then use only what you want. It is the triangles that matter, not the vertices. I don't think there is an issue with unused vertices in the vertices array. You'll have to run a test to be sure.
Edit: I just tested it, and oversizing the vertices array works just fine. If used, the uv array the normals and the colors array will have to be sized to match the vertices array.
Thank you so much for this tip. Creating new arrays for vertices, triangles, and uv coordinates for each mesh was just not efficient enough for what I'm doing, strea$$anonymous$$g procedural meshes in a 2.5D game. Only worrying about triangles should help out a bunch with garbage collection. I really wish Unity's $$anonymous$$eshFilter would accept an ArraySegment for each of those properties.
