Turn displacement map into geometry for 3D printing

Rhino
#1

Hi. I have modeled an organic object for a client with bump/displacement map for the veins on skin. he’s happy with the design but now I have a problem for the final export - the bump map is only for renders so the exported geometry doesn’t include any of the surface bumps.

I know in Modo there is a way to bake cached geometry, Can I do something similar in Rhino?

#2

ExtractRenderMesh command

#3

thanks. just tried the command works. however because it converts the surface to mesh now it cannot be exported to STEP file which the client demands.

#4

Bump/displacement maps are meshes - not surfaces. Therefore no way to get one directly as a surface for export. You could try extracting the mesh then using Drape with a fairly high CV count over the mesh, or Patch with a lot of spans and low stiffness - either way this will still result in a smoothing over of the sharp detail - plus a relatively heavy surface.

You don’t need surfaces for 3D printing, meshes are actually what is needed (generally .stl) so why are you exporting as STEP?

#5

Thanks.

He insists on having a step file otherwise won’t pay.

I am trying rhino 7’s quadremesh to subD. it’s taking a long time to generate. will report if it works.

#6

Sounds maybe like he’s ‘undereducated’…

1 Like
#7

Yeah, the reason for demanding a STP file might be due to a need for CNC machining, which opens up a new set of considerations.

It possible there can be issues with a very complex organic model for machining so even supplying an STP file may require significant adjustment or modification.

In this case I typically tell clients any machining issues will be the client’s responsibility.

#8

I simply went on the assumption that the topic’s title was correct. It is also possible to machine from a mesh file - I used to do it all the time - but the shop doing the machining has to have CAM software capable of doing so.

#9

Agreed, and from personal experience I often come into contact with people that don’t understand the difference between 3d printing and CNC machining.

Although it possible to machine from a mesh, some CNC service, even if they have the right CAM software choose not to do so. Its my understanding toolpath optimization cannot be performed on an imported mesh, so the CAM software must create it own mesh from the nurbs surfaces. Toolpath optimization is necessary for better surface finishes and improved cutting speed as well as reduced wear and tear on the machine.

#10

the client has limited knowledge but obviously been told to obtain a step file.

I am happy to report that QuadRemesh to SubD works. took a couple hours to process but the exported STP can be open by Rhino itself. I hope this is considered job done.

#11

I’d be interested to know how many surfaces are in the polysurface it generated and how close the result was to the original mesh.

#12

ExtractRenderMesh generated close to 2 million triangles

with Quadremesh you can set any number of quads, 15000 took about 1 hr to process. the result is not as detailed as the mesh because the quads are still visibly much larger than the mesh. but we can always set the quads higher…