Projection mapped onto an undulating surface, then Image Sampled

Replies to This Discussion

Permalink Reply by David Rutten on December 12, 2016 at 3:20pm

What am I to visualise for 'projection mapped 3D surface'? How is the colour data 'embedded' in the surface? Rhino can have materials and textures/decals assigned to a surface, but there's no way to embed that data into the surface. It is possible for meshes.

Permalink Reply by David Rutten on December 12, 2016 at 3:30pm

Incidentally here's a presumably simpler and more flexible way to find the nearest colour in a fixed palette:

Attachments:

• imagesampling.gh, 3.7 MB

Permalink Reply by Ben Julian on December 12, 2016 at 3:40pm

Thanks David. Yes, let's stick with meshes. Can I link to a projection-mapped mesh in rhino? I see this post on 3D printing that saves off embedded color data in either VRML97 or X3D format but I'm not sure how to achieve it in rhino: 

http://www.shapeways.com/tutorials/exporting_to_vrml_and_x3d_for_co...

As far as visualizing "proj mapped 3D surface" I uploaded a projection map of a face to the original forum post. I like the way the projection shears off the side of the surface.

This is eventually going into RhinoCAD btw after the image gets divided into colors.  

Permalink Reply by David Rutten on December 12, 2016 at 3:44pm

I presume that vertex colours are imported correctly from Rhino into Grasshopper, but I haven't tested this lately. If you import a file such as VRML which contains vertex colour they should persist. Then, instead of sampling the mesh like you do with the image, it would be much easier to just get all the colours for all the vertices.

It may be possible to sample in between vertices as well, not entirely sure everything works the way it's supposed to for this...

Commonly meshes also have texture coordinates embedded in them which allows one to wrap an image texture correctly onto the shape, but Grasshopper cares not for either textures or texture coordinates.

Permalink Reply by Ben Julian on December 12, 2016 at 3:53pm

How do I "get all the colours for all the vertices"?

What's the best way to compress the GH file so I can send to you? it's 25mb in its entirety. Can I send it to you offline? 

Permalink Reply by David Rutten on December 12, 2016 at 4:00pm

The Deconstruct Mesh component will give you all the vertices, faces, normals and colours.

GH files are already compressed, I doubt you're going to make great gains compressing one again. Any chance you can limit the file to just those components that are relevant? You can remove large swaths of network by internalising data inside inputs. This will make the current solution permanent and you can then delete anything to the left of those parameters.