I’ve made a River Flow material and make an instanced material out of it, but when my teammate was putting it to the map, there was clipping between meshes the use the material, like so:
How should I edit the material to stop the effect(problem of Material)? Or should it be the responsibility of my friend(problem of Splines Tool)?
Hey, have you tried using the WorldPosition node and a ComponentMask node to filter the X and Y values? That’s usually how seamless textures are created.
That is an with the spline tool built into landscape I think, I created a RiverTool blueprint that creates a spline mesh that allows you to modify the tangents and spacing for each point.
I uploaded it to my DropBox here a while ago, give it a try if the material tweaks don’t help (it is based off of 's road tool tutorial with some minor tweaks).
Hope that helps, I am working on a better version of using some of the techniques shown in the recent Spline tutorial put together by Epic’s Zak Parish, will likely include it with my next release of the ocean/weather system linked in my signature below. 
I’ve made the wave using the World Position Offset, don’t know if that will affect the problem. What’s the relation between filtering the X and Y values & creating seamless material?
