Controlled Attrib Transfer

[gaurav]

Hello folks,

How would you approach a situation something like in the following image ?

Basically i need to get a ring around the area where sphere touches the plane.

Width of the ring should be constant and it should be able to grow and shrink as the sphere touches and leaves the ground plane while bouncing around.

Though, what i am doing using attrib transfer is kind of working here, but loosing ring shape at times @ frame 12,13 etc.

Any other ideas or suggestions ?

Thanks,

attribTransEdge.hipnc

[SpencerL]

Hello folks,

How would you approach a situation something like in the following image ?

Basically i need to get a ring around the area where sphere touches the plane.

Width of the ring should be constant and it should be able to grow and shrink as the sphere touches and leaves the ground plane while bouncing around.

Though, what i am doing using attrib transfer is kind of working here, but loosing ring shape at times @ frame 12,13 etc.

Any other ideas or suggestions ?

Thanks,

Cookie Sop > Crease option should do the trick

[Macha]

Another idea: raycast, store distance an then clip min max ranges.

[zarti]

hi ,

id suggest you to build that 'fixedwidth' as a geometry .

after that , you can scatter points over it / + subdivide the mesh you are transferring attris to

for better performance and accuracy ( depending on your case ) .

use AttributeTransfer SOP in an ' official way ' .

--

there is a Red Null SOP containing the control of the FixedWidth you want ..

-

-

attribTranzEdge.hipnc

.cheers

[old school]

Here's yet another example this time using an asset built in Houdini 12 using the Fluid Source SOP instead of the Iso Offset SOP to build the volume representations of the incoming geometry. By controling either the edge location or feather width, on both input surfaces, you control the boundary volume generated.

This approach is entirely topology independent and you end up with a volume to use the Attribute From Volume SOP or use the volume at render time to tint stuff. Scatter points in the volume and use point cloud look-ups, whatever.

It doesn't matter if you have a primitive sphere (which I did use on purpose) or a NURBs surface, it just works.

I forgot to add pscale attribute support to the asset. Oh well just need to raise that up from the Fluid Source SOPs inside the asset. This way you can add pscale either with expressions or paint operations to control the thickness on top of the edge location and feather width.

surface_intersection_volume_v001.hip

surface_intersection_volume_v001.otl

[gaurav]

Wow !! Thanks for the replies guys.

All your tips are really helpful and gives me other point of views to look at the situation.

Hi zarti, Very clever. It never clicked me to use clip this way.

Hello Jeff, Thanks a ton for the otl. Using volumes is indeed very robust solution and topology independent. I just installed H12, Fluid source sop looks so much fun.

I am very much excited over the possibilities.

Cheers,