wrapping geo like Wrap3

[Oliver Markowski 9]

Hey guys,

I guess many of you have seen this: Wrap3

Has anyone got an idea if this is possible with Houdini? If yes I'd be thankful for some pointers.

Cheers

Oli

[Atom 1,206]

I think you could do that with the RAY sop. You may need to resample the source or the target so they have the same number of points.

[Oliver Markowski 9]

ray_sop is not able to do that I guess since it only projects points. Wrap3 actually "wraps" a mesh around another mesh.

Anyone else?

[schwungsau 281]

point clouds would better then ray sop....

*edit:
actually ray-sop and then point cloud look up works best.

Edited February 14, 2017 by schwungsau

[schwungsau 281]

the only save way would be unfold the geo in one 2d plane (pretty much uv unwrap) for boeth geo and match uppoint wih point clouds radius. to make it in vex it could a little tricky..... i 've never did it in houdini...

[f1480187 758]

Seems like an advanced tool for me. I think it's not possible in Houdini, unless you'll write such solver from scratch using basic Houdini tools. You need to know algorithms behind this technology. Ray SOP basically does a raytrace. It is somewhat useful to conform meshes with almost identical shape, but it won't give you advanced results like transforming a base state of modeled hand into a gesture from scan. Same problem with point clouds.

[petz 431]

i don´t know this tool but from watching the video i guess that it uses a non-rigid icp algorithm to match one geometry to another. there is no "out of the box solution" you can use in houdini but it isn´t too hard to wire together something that works in a similar way.
please take a look at the attached file. it uses some pre-definded points on both geometries to guide the general alignment and deformation. if you want this to work without any user input it might become more tricky but should also be doable ...

hth.
petz

 

non_rigid_icp.hipnc

[MrScienceOfficer 53]

That's beyond cool...  Thank you so much for sharing, petz.

[Igor 2]

This is very very good File! Thank you Petz. I did not know it is possible with Houdini.

[Oliver Markowski 9]

thanks for that file petz! After looking at it I feel like I know nothing about Houdini  Need to dig into all the nodes now! Thanks a bunch!

What exactly are you doing in CHOPs?

Cheers

Oli

[AaronAb 7]

New point positions based on the reference geo are being interpolated in CHOPS. Here is an example from years ago with similar functionality

 

[samuel 1]

Hey guys, sorry to ressurect the topic.

I'm just new to python and I can't quite understand what's going on in the python node inside 'subnet'. Can anyone help me? =O

 

cheers

Edited February 22, 2019 by samuel

[samuel 1]

Alright so I just finished to study python (solo learn app ftw) to figure out how the python code works. For those interested:

 

node = hou.pwd()
geo = node.geometry()
#these came by default with Python SOP, don't change it.

nodeTrans = node.node("/obj/geo1/subnet1/objnet1/OUT")
#nodeTrans receives the points and its data resulted of the objnet/extractgeo SOP

mat = nodeTrans.worldTransform()
#mat receives a matrix with the transform data of the points in the world, translate and rotate information

matAttrib = geo.findGlobalAttrib("mat")
#matAttrib receives the 'detail attribute' data from mat. In the first time in the loop it has zero data, so \/

if not matAttrib:
    matAttrib = geo.addAttrib(hou.attribType.Global, "mat", mat.asTuple())
#Turns the matrix data of mat in 'detail attribute' as Tuple

else:
   geo.setGlobalAttribValue(matAttrib, mat.asTuple())
#if matAttrib already has something in it, put these values into 'detail attribute'