find point where line intersects 3dface

[jdfnnl]

Is there a way to trim this ridge line (in red) to the roof plane in order to resume drawing the valleys that are created here?

 

[Michiel.Valcke]

you have asked a similar question in another post. You can do a similar thing here. If the line does not cross the face, extend the face to find the breakpoint and cleanup afterwards.

https://forums.autodesk.com/t5/autocad-forum/trim-lines-to-3dface/td-p/12168276

[Kent1Cooper]

Search is your friend.  There's an extensive topic on this very question, >here<.