I used the landscape generator to create two mountain ranges.. They go edge to edge and have a weird clipping effect. I want to join them together and have the vertices joined cleanly and look normal. How could I go about this?
You can combine two landscape using the bridge tool.
Select one of the landscape in object mode and move it away from the other slightly.
Select both landscapes in object mode
Join the two object together, Ctrl J
In edit mode select both edge loops between the landscapes.
bridge them together using the bridge tool, W -> Bridge Edge Loops
Number of Cuts: adjust this so that the generated polygons look square
Interpolation: Blend Surface, has the best look for bridging terrain
Smoothness: adjust this to your liking
Assign a gradient to both of them, from black to white along the z-axis. Render this from the top to get the combined heightmap. See this question:
Create a new plane and assign the rendered heightmap.
This is fairly quick, easy and gives excellent topology.
I recommend to use Boolean modifier: