Memory management and performance of many terrains

Unity Engine
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1

Hello,

My plan is to make a kind of autobahn car racing game with very long tracks and big open world. It is going to be released on iOS.

Many square terrains will be attached together, stiched with a tool. For the road I found the EasyRoads3D. I am not sure how to achieve several lines yet. Street crossings etc. with be modelled seperately. For the car physics I found another asset. The environment should be eye candy. Terrain patches should be loaded asynchronously. For the traffic I am not sure if there are (code) assets to look at.

My question is: Do you have any experience/assuptions with memory and performance on iOS concerning this idea? Is there a convenient way for the artist to see and edit the whole long track in the editor? Or should every patch be saved in a seperate level? Or can i have one level with hundreds of prefabs with terrain patches? A side problem is a zoomable map with all streets.

I am an experienced game developer, but relatively new to Unity3D.
Any thoughts welcome!

Kind regards,
Chris

2

Unity terrain performance on mobile devices isn’t best possible. But there are terrain plugins in Asset store that work better with mobile devices.

3

Thanks for the warning. I will check for alternatives for Unity3d buildin terrain. Unfortunately currently i don’t have mac hardware to run some tests on iOS. In the store i found scripts for slicing, merging and dynamic loading of terrain (patches) but they all have its drawbacks.

4

My best advise could be the following :

  • Make sure you cannot see the connection between the Racing tiles (Road + some environement en each side) and the background tiles (large tile for the environment)

  • Make the Racing tiles have low vertex count as possible to access to the Dynamic batching (Be sure those tiles share the same texture//Material)

  • If you need transparency in your Racing tile, create 2 meshes for each tile (one with and one without alpha) and make sure the mesh with alpha only include alpha part of your mesh (do not hesitate to cut the area if need)

After it should be a piece of cake.
All will depends if you are using special shader or simly lit lightmap.

5

Thanks for the answers. We finally did it with unity terrains of geometrical and data size of 1000. The camera sees always about 3 of 9 loaded terrains and the framerate with objects is 20-30 on iOS, which is ok.