Hi all, im new on this forum. Im trying to understand how games that use Heightmaps texture their terrains, where they use several textures on especific coordinates of the cenario, with a gradient mask beetwen the textures, to get more realistic effects.

I believe the technique you're thinking is "splatting". A quick google search turns up plenty of hits.

If you know shaders this will be easy. Basically you have multiple tiled textures like grass, dirt, rock. These are repeated across the terrain however many times you want to repeat. To decide where to use grass, rock, dirt, you use a texture RGB, and lookup R = grass, G = dirt, R = rock.

If you have a heightmap, typically people will use grass if height < 10, dirt >10 & < 20, rock > 20.

If you need something fast, you can just make a big texture like 2048x2048 and get something like L3DT or some other terrain tool, and export a big texture and just slap it on your entire terrain.