Need terrain sourcecode

Hello, we strongly need terrain sourcecode, because we find that place object through terrain give more efficient result and more optimized than simple prefab placing, especialy this about grass.
So we want add:

-Rotation for object, which we set manualy, for example put the house on
the terrain we set rotation, scale of house then click paint.
-Comfortable drag and drop UI for trees, grass, textures and etc.
-Support custom shader.
-Far and near pixel error for restrict tris density effectively.
-Support custom wind.
-Support split terrain into parts.
-Work with pbr.
-Terrain deformation.

this is our project and we put third place in the top.

Also we develop our site
p.s. full engine source code will be helpful a lot!
tnx for pay attention.
sincerely Teiwaz Studio.

I’m not sure why you’re asking here - Unity Answers is a technical community forum. For source code access, you need to buy an enterprise licence from Unity: 2D, 3D, VR, and AR software to develop cross-platform games and mobile apps. | Unity Store

If you want to add suggestions for Unity to implement in future versions, you should add your voice to

Or, if your needs are significantly different and you have the technical capability to do so, you can always roll your own terrain solution.