Apologies if this has been asked before (not even sure if I've asked it in the past)

How can I overwrite landscape weightmaps? If I let Houdini create a new terrain, then everything works fine, it find the landscape layer and write the masks as expected. But if I try to apply it an existing one that's in the scene I get some garbled results, like it's writing masks to the wrong layers and there seems to be no logic to what layers it picks from what I can see.

To clarify cos of unreals confusing naming system - I am talking about paint layers specifically

Hello,
I also have this problem.
I want to paint a weightmap near a procedurally generated road and everything works except that the HDA doesn't replace the weightmap values but it just adds to them.
When i modify the road and regenerate HDA that outputs the weightmap the old state of the weightmap stays present. (Shown in the screenshot)
I hope that there is a solution, because this totally defeats the purpose of procedural weightmap painting in my opinion.

I immediately found the solution after posting 0_0
But i am not sure this works as it is intended.
Setting the weightmap layer to non-weight-blended using the i@unreal_landscape_layer_noweightblend attribute clears the layer before writing the new weightmap data.
Setting the attribute to 0 (default) causes the output weightmap to be added to the old state, like in the picture from my last post.
(Weirdly using the other non-weightblended attribute that uses the mask names doesn't have this side effect)

This leads me to believe that there is a bug with the output of weightblended weightmap layers when modifying an existing Landscape. (Houdini 20.0.544)