belusart Posted May 16, 2019 Share Posted May 16, 2019 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 Quote Link to comment Share on other sites More sharing options...
Atom Posted May 17, 2019 Share Posted May 17, 2019 For a more grid style scatter try a node recipe like this, using pointsfromvolume. Quote Link to comment Share on other sites More sharing options...
belusart Posted May 17, 2019 Author Share Posted May 17, 2019 Thanks Atom! I will give this a try tomorrow. Quote Link to comment Share on other sites More sharing options...
belusart Posted May 18, 2019 Author Share Posted May 18, 2019 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. Quote Link to comment Share on other sites More sharing options...
julian johnson Posted May 19, 2019 Share Posted May 19, 2019 I wonder if intersect_all() would give you what you need.. lidar_test_intersect.hipnc Quote Link to comment Share on other sites More sharing options...
julian johnson Posted May 19, 2019 Share Posted May 19, 2019 Added projection from the top...lidar_test_intersect2.hipnc Quote Link to comment Share on other sites More sharing options...
belusart Posted May 20, 2019 Author Share Posted May 20, 2019 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! Quote Link to comment Share on other sites More sharing options...
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