Hi guys,
I wonder how you would approach creating a mesh from a point cloud in Houdini, or maybe Maya? I have exported a point cloud of a mountain from PFTrack as a .cmd file and want to create geometry from the points so it can receive shadows. The surface is pretty rough, so I can't use triangulate2d sop because it gives me nasty geometry (when using a point sop to get them back in ther original positions). Also, I don't have that much experience in Houdini only a couple of weeks, so maybe there is an easy way that is pretty obvious?

I have about 5000 points or so, so it would be very time consuming to do it by hand. Of course I don't need to snap to all the points but still it would be a pain to do it by hand.

Is there any way to create a mesh from a point cloud so it looks decent, either in Houdini or Maya? It doesn't have to be exact, but a good appproximation as a base so I can tweak it a little by hand where it needs to.

Thanks in advance

Depending on how the points are positioned you perhaps could try using the Particle Fluid Surface SOP. But that might not give you the desired result.

how about this,

- make a big grid that all the cloud points are positioned above
- stuff the Y positions of each point into an arbitrary attribute
(name the attribute tempY maybe)
- zero out the y component of each point so it lies on the grid
- attrib-transfer the tempY attribute to the grid
- stuff the grid's newly-transfered tempY attribute into TY
- adjust the attrib-transfer to tweak the grid's terrain to your liking

this will work less well if there are big gaps in your point cloud, but it might give a good start for some hand-sculpting.

hope it helps

thx for the replies,

I've tried with the Particle Fluid Surface SOP but it gets to blobby. I've tried different setting and so but it still is more like fluid than a mountain mesh.

nobodyinparticular, I've tried your method before but it tends to get too choppy so to speak. There are some unwanted peaks here and there and it doesn't look good.

Anyway, I will be trying other methods as well but if anyone has more suggestions please share. I've attached the Houdini file and a still from the footage if you would like to see the point cloud and what I want to achieve.

Cheers

Your data doesn't look like it comes from elevation data. I think you probably need some sort of adaptive local triangulation for data like this. Try using Power Crust [userweb.cs.utexas.edu].

You can try Meshlab. It has point cloud support. It is free software. If you are under Linux, you can run it under Wine


http://meshlab.sourceforge.net/ [meshlab.sourceforge.net]

Ah, but I realize that you can also use PointCloudIso if you have normals:

http://www.sidefx.com/docs/houdini12.0/nodes/sop/pointcloudiso [sidefx.com]

Another thing that you can try if your points do not overlap (ie like a lidar scan) is to use triangulate2d to do a Delaunay triangulation of your points (best) then get your y position back w a point SOP. Converting to a volume and using volumeSurface SOP it's also nice as it gives you nice and even tris

grayOlorin
Another thing that you can try if your points do not overlap (ie like a lidar scan) is to use triangulate2d to do a Delaunay triangulation of your points (best) then get your y position back w a point SOP. Converting to a volume and using volumeSurface SOP it's also nice as it gives you nice and even tris

This works a treat, thanks.

Hi all. I did a rough survey of some terrain & imported the data into Houdini as a .csv file & 2DTriangulated it but I'm not sure how to progress from here. The survey was based on a grid but some of the points are random.

grayOlorin
Another thing that you can try if your points do not overlap (ie like a lidar scan) is to use triangulate2d to do a Delaunay triangulation of your points (best) then get your y position back w a point SOP. Converting to a volume and using volumeSurface SOP it's also nice as it gives you nice and even tris

Could someone please put up a screenshot of how the Network View showing the nodal set up to do this, that would be unreal. Otherwise some more details on what nodes exactly. I'm using Houdini 17.

I attached a screenshot of what I've done so far, which hopefully helps.

Cheers.