Jump to content
belusart

Project points on geo

Recommended Posts

I want to project points on some building or even scatter them in a grid like fashion but can't figure out the best way to get points on all the geo.  Right now I took some workflows from the lidar effect from this video, https://vimeo.com/132679428, which for the most part is working how I want.  Right now, I have a city block with subdivided box geometry projecting points on each street corner group of buildings.  The problem comes in when the projection is blocked by surrounding geo and the "hidden" areas get missed.  I tried 2 other methods that are in the file.  One is where I scattered points on all of it but this ends up being random and not grid like.  The second is where I subdivided the city block the did an add to put points on the geo, but isn't really doing what I want.  With the projection, I'm taking a large chunk of buildings to try to get it all in one large stroke, maybe thats not the best way either.

So my question would be is doing a projection the only way to get what I'm after or is there a better way to scatter points on the geo in a grid?  Any help would be appreciated.   Attached is my file with an alembic city block you'd just have to re path in the geometry file named city.

 

 

lidar_test.hip

cityNorthTest_v001.abc

Share this post


Link to post
Share on other sites

For a more grid style scatter try a node recipe like this, using pointsfromvolume.

Untitled-1.jpg

Share this post


Link to post
Share on other sites

I tried this out and is giving me grid of scattered points but the only issue I'm getting are the point are a volume.  Atom, are your points a volume as well or were you able to stick them them to the surface?  I'm been trying to look through the help file at different nodes I could ues but haven't found anything yet.  I also do have a question about the convert you are using, you have a note about remove polygon soup.  Would that just be a convert to polygon because it's an alembic file? 

I'm coming from a max and maya background and a lot of these things I still learning how it all works in Houdini.  I used the normal node but I couldn't really tell if it was doing anything, maybe just averaging all the normals?  Just curious what you used it for.  I did get a scattered volume even when disabling the convert and normal but I'm guessing theres a reason you used them both.

I'm going to dig in again tomorrow and see what I come up with for sticking the points to the surface but if you got anymore pointers, I'd appreciate anything you got.

Share this post


Link to post
Share on other sites

Thanks Julian.  This is a pretty nice setup and pretty simple.  Although I'm still in the beginnings of learning VEX and not very far along down that path.  I will use this to learn from though.  I mostly understand what going on in the expression but I'll have to do some more research on the stuff I don't know yet.  Thanks for the help!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×