I have made a grass texture. How can I create grass on my own imported terrain ? On Unity terrain there is a brush for creating folliage but I would like to do that on my own landscape.
I don't think you can. What you can do is to use Unity's Terrain, but use a Heightmap (made from your Terrain) for it.
terrain != mesh You've got to pay close attention to the words being used. Most of the time in computer programming, specific words have a single, specific meaning. In this case, terrain denotes a special kind of object that the game engine communicates with in a distinctive way. You can make a mesh of a landscape in your 3d app and import into Unity, and you may refer to this mesh as a terrain, but Unity does not recognize this as a terrain because Unity is a computer program, and computers are stupid. A computer only knows the last thing somebody told it to know. Unity knows that a terrain is a special type of mesh that it creates in the engine itself, and Unity has special algorithms for working with it. But Unity cannot understand that just because some assembly of vertices you brought into the engine should be considered the same thing just because you want it to be. So, if you want to be able to instantiate grass on your imported mesh, the first place to start is learning all there is to know about Unity terrain's (google that to find the documentation), and then from there start searching for the more specific question : "How to use custom terrain Unity." You'll find more words that may be unfamiliar, like splatmaps, etc. You'll probably need a few days of studying just to start getting an idea of what some of the usual methods are. There is more than one method to do what you want to do, and I don't know much beyond the general theories, so sorry I can't give a more specific answer. But you'll want to know all the options anyway.
With a "mesh placement" or "mesh scatter" tool. Polybrush, which is part of the ProCore series that is now owned by Unity, is an excellent free tool but requires Unity 2017.1 and placement is handled by "drawing" them in the editor. http://www.procore3d.com/polybrush/ https://assetstore.unity.com/packages/3d/polybrush-beta-111427 Mega Scatter is a paid asset that has been around for a long time and the developer has a good reputation. It has support for the latest releases as well as older ones as far back as Unity 3.5. Object placement with this one is done using splines and textures. https://www.assetstore.unity3d.com/en/#!/content/14954