Hello, first of all, I have been playing with Houdini for some time now and I find it extremely capable (and fast) for procedural city generation (from footprints) unlike other apps in which I have been working previously..

But I'm having problem to understand (and haven't found solution anywhere) how to do local edits on procedurally generated geometry - for example manually selecting 1 footprint and changing some parameters only for this selection (like building height for extrusion..) or moving its points to change footprint shape...

The use-case would be like this: Houdini procedurally generates a city so that it will do most of the work and then a user will fine-tune details by adjusting few parameters on certain problematic places/buildings and after that the city will be re-generated (which is faster than modifying already-generated 3D models either in houdini or other 3D application)


Here is my simplified setup - I just imported a couple of footprints and then randomly extruded them in foreach loop



Now I want to:

1) select one of these buildings by clicking on it and now somehow edit certain parameters like building_height that will affect only this selected footprint (because if I change it in PolyExtrude node, it will obviously change it for all footprints)


2) next, I would like to do is to change footprint's shape by moving (translating) its points. Well, I managed to that by setting display flag on source footprint and template flag on output (which is extruded footprint in this case) and while this is cumbersome but works - it is extremely slow when running on complex code with lots of buildings because It has to re-generate all buildings with each movement of a point.


Can you please provide solutions for these problems or please explain what are the best-practices with these use-cases?
Thanks