I’m trying to project some geometric patterns on Alias’s surface in rhino7
so I exported my alias file as igs and imported it in Rhino as a nurbs file , it worked.
but when I use grasshopper to make some patterns on surface , it doesn’t work in.
if I do it on one surface, it works but if I do it on multiple surface, it’s failed. how can I fix this problem?
please help me to solve this problem
Hello @Hyeon_JEONG
Creating textures and patterns that span across multiple surfaces is a unique challenge in Grasshopper and there are many ways to approach is depending on your objecting and the circumstances of the surfaces that you are working with.
The first thing I would do Is export your file from Alias as a STEP instead of Iges. I typically have better results with step format. There s also a great plug-in by DigitalSculptors that will import native Alias files directly into Rhino and it includes grasshopper nodes so that you don’t have to convert your .wire file. You can install it through the PackageManager command in Rhino. Its a great tool and I high suggest it if your workflow requires moving data from Alias frequently.
As fr trying to map your texture across multiple surfaces: In NURBS polysurfaces (or shell surfaces in Alias) each individual subsurface has its own UV space. If your surfaces are untrimmed quad surfaces you can merge several of them together into once surface for the area that you want this texture to reside. If you cant do this you can try joining together the surface that you where you want the pattern to be, and if its a quad polysurface you can use the quad remesh tool to create a “proxy” surface. Convert the quad remesh to a subdiv and and then convert that to a Nurbs surface with surface packing enables to try and get a clean single surface to carry your texture. These are just a few idea.
If your want someone to help you you’ll have to upload your files to this thread. I would suggest internalizing your input geometry to your grasshopper file. Myself or someone else may be willing to take a look at your grasshopper definition.
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Thank you for your kind answer, I tried to import Alias file to Rhino with the plug-in, I don’t know the reason, it doesn’t work. so… if you don’t mind, Can you help me to solve that? this is the first time to use Grasshopper and Rhino, it’s bit confused.
here is the file as Rhino file imported by step from Alias and Grasshopper. and I’d like to make them as a reference here ( fading pattern?)
1.3dm (343.8 KB)
grasshopper pattern1.gh (24.8 KB)
Hello - as far as I can see you’d need to create a single surface as a target surface - a qiuick and dirty way to test this is to mesh your surfaces or some of them and Patch the mesh - trim and shrink the patch surface to use as a morph target-
-Pascal
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Or you can set up a single surface beneath the given design surface - I see the base surface of the pattern has linear edges along the x-axis. Then you can apply your patterning definition to the single surface until it creates a point set. Before making the actual pattern, you need to project the points to the given surface (Polysurface or whatsoever) to constrain the points to reside in the design surface (the given). That way, the point list or datatree will keep their data structure intact. Then with the adjusted point set, you can continue your pattern-making logic. For the fading effect, I am not sure how you would achieve the smooth transition back to the given surface. By the way, you first need to sort out your surfaces - some of them are not even touching.
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