Rendering Extremely Large Meshes

Unity Engine
1

I currently have the need to render meshes with 5-25 million triangles in them. These meshes are calculated at runtime and I want the ability to load the VBO to the graphics card and store it there between frames. I currently render them using the GL library, but that has the disadvantage of clearing the VBO every frame (and it takes around 1300ms to load my 5 million triangles, so clearing every frame is not an option). Does unity have the ability to support extremely large meshes? If not, how should I go about rendering this.

2

Unity 2017.3 supports it. You will have to wait for that (beta or otherwise). Platform roadmaps | Unity 32 bit mesh index buffers.

Otherwise you’ll have to chunk it.

3 Likes
3

any chances there’ll be a beta or preview of 32bit mesh index soon now?

4

2017.3 beta starts probably in October, that’s 2-4 weeks I guess.

1 Like
5

25Mil triangles… unless its a console game you could well kill alot of machines asking it to do that plus all the other stuff.
Dont forget its impossible to actually see that much detail in one frame. Perhaps its best to chunk it, as parts get further away, lower the LOD.

6

I am a beginner, I am creating a basic FPS game using a terrain. When I painted the 3d grass on you can only see it when your really close. How do I make it so that from the FPS controller you can see the grass from far so that it doesn’t look bare?

7

So you painted grass as geometry right on the terrain mesh? Not sure what you do there but you should consider to use Unity terrain or at least you have to use some kind of LOD system for your scene. Splitting up big meshes is always a good idea as it can be culled. Especially Grass is something you don’t want to be vissible (in full detail) when you are further away. And this is what the Unity terrain can help with.

Edit: The 32-bit Mesh buffer is already available for 2017.3 Beta. I just imported a mesh with 2 million triangles!

8

Set the detail distance in the terrain settings. If you want to increase it further than the inspector editor allows - set it in code. (You can set it in Debug inspector mode but it will jump back if you ever set it back to Normal - Right click on the Inspector tab name)