2D shape-> Puffy relief model


#1

Hi Forum,

I have a beginner question. I have a 2D shape of a human figure silhouette, and I’m wondering if how I can extrude this shape into a ‘puffy’ hemispherical relief.
Something similar to this image.

Since it’s a complex 2D shape, I’m not sure how to proceed easily in making this structure.

Any advice/tips, which tools to look at, etc would be much appreciated. I’m using Rhino 5.

thanks
Dreko


(Brian James) #2

I’d use the ApplyDisplacement command on a plane with a custom 2D texture as the input. Here’s a sample with a flower texture I whipped up to help explain.

OrchidDisplaced.3dm (589.9 KB)

And here’s a video tutorial on displacement in Rhino 5…


#3

Brian,

Is ApplyDisplacement preferable to using Heightfield?

If the desired result was a nurbs surface instead of a mesh, what would be the best way to do that from an image?


(Brian James) #4

I think it’s more flexible due to the editable nature of it being an object modifier. It really depends on what the goal is and where you’re taking the geometry though.

Reverse engineering is the process of making a NURBS version of a polygonal mesh model. You can read more on the subject of using Rhino for this manual workflow here http://wiki.mcneel.com/rhino/reverseengineering
With all that said, and mainly just to keep expectations under control, you can use Rhino to reverse engineer a mesh if you’re skilled at drawing out curve topology for surfaces, i.e. four sided patches. You can also use commands like Drape to wrap a surface over a mesh from a single Cplane normal. In this case, that might be fine if a NURBS version is desired. The control point density of the drape surface determines the level of detail you’ll get.


#5

Hi Brian,
Sorry, I think using that ArtCam image was incorrect. I don’t have a greyscale image to build a relief. What I have is a simple 2D vector shape (human silhouette)

I’m looking to take this complex 2D flat shape, and find a way to ‘puff’ it up in a fairly easy fashion.
Any thoughts?

thanks!


#6

“You can also use commands like Drape to wrap a surface over a mesh from a single Cplane normal. In this case, that might be fine if a NURBS version is desired.”

Drape, OK. I did not know if there was any newer command that worked in a similar way.

I understand there will be a difference between the nurbs approximation and the mesh, but that could be acceptable for some things.


#7

@BrianJ What settings did you use for the orchid?


(Brian James) #8

They should be in the file posted… in the Displacement section of Object Properties. I think I used ‘very high’ detail and raised the memory available to 512.


(Brian James) #9

I would make the grayscale image using your profile and a 2D painting program or image editor. The displacement is controlled by the transitions of black to white so a black fill of your silhouette followed by inverting the selection, feathering it and finally deleting the outer edge should give you a soft form.


#10

Hi, you can also get an interesting and quick result with Rhino PhysX plugin (rpInitialize + rpCloth + rpSetClothParticleWeights):



#11

This example was made in two phases, the first phase has _FabricStiffness parameter set to 0.5 and all boundary control points have rpSetClothParticleWeights set to zero (not move). Then rpBake. Then the second phase _FabricStiffness parameter set to 0.1 and the ring + boundary control points selected (I used _SelBoundary command in both cases) with rpSetClothParticleWeights set to zero. Important! Scale up your mesh surface because it tends not to simulate properly on the small scale (this example has a diameter of approx 900cm). Good luck!


#12

Hi guys,

Thanks for the replies, however I’m finding getting this Alpha to perform with a cloth simulation is not quite what I was hoping to use…

Any other ideas? The advice on feathering the edges of the 2D form won’t quite work. “. The displacement is controlled by the transitions of black to white so a black fill of your silhouette followed by inverting the selection, feathering it and finally deleting the outer edge should give you a soft form.”

Because of the 2D shape

The feathering isn’t quite uniform. I.E. If you feather the shape so the thinner areas look good, the wider/larger areas don’t benefit from the feather. Manually painting in a smooth and perfect gradation isn’t looking good.

A number of years ago at Siggraph, there was a free downloadable program, that was based on the premise of converting 2D into 3D models easily. One feature it had, was you could import a 2D shape, and it had a interactive slider, that ‘puffed’ up the surface within the 2D shape in a more controllable fashion. (i.e. uniform z heights)

Can’t locate the program anymore, but looking for something like this. Artcam allows a fixed height unlike the RhinoPhysX look/effect.

thanks!


#13

There is a special plugin for this - http://www.tdmsolutions.com/products/rhinoemboss/


#14

Thanks Cadmaster

I’ll take a look at it…
Here I just made it in a CAM program… I think I can export this out as a STL format, then bring into Rhino to rebuild

This is what I was looking to accomplish entirely in Rhino…
thanks


#15

Wow, RhinoEmboss as a plugin is more expensive than Rhino!


#16

This example looks like a lot of spheres within a given silhouette + BooleanUnion.
Should not be impossible to script something like this in Rhino or I’m mistaken?


#17

Yeah, it does have that spherical quality to it…
Here I’ve smoothed it out in MudBox

It’s the idea however…
Now I’ve got to attach it to the 3d model…


(Brian James) #18

Just for fun, here are two results using Rhino 5 only.

Puff.3dm (404.5 KB)

I’m uploading the displacement surfaces and embedded textures to keep the file small but here are the steps I used on both versions.

  • ApplyDisplacment
  • ExtractRenderMesh
  • Smooth (I use a smooth value of 1 multiple times versus a large value once). I will also turn on ctrl pts for the mesh and use SelBrush to selectively smooth chatter if needed.
  • ReduceMesh (either by number or planar only)

The softer one was made with an edited version of the Maggie image which was embedded in the 3dm (Options>Rendering>embed textures)


#19

Hi Brian

Thanks for those uploads. Do you think your procedure steps will allow me to get the look/effect further along the lines of what I’m looking for? No flat areas (like in the last step) but instead, fully ‘puffed’ up like in my examples?

thanks


(Brian James) #20

I think it’s all about the texture… so practice your painting skills for something like the spherical/3D metaball looking version and you can get closer. Or use a mesh sculpting program if don’t want to tweak images.