I need help with some surface mapping issues

I want to use surface mapping to create default contoured mapping for some 2 rail sweeps. I can do this, and it works well, however, I ALSO need to do more modeling/splitting/joining etc for those surfaces and still preserve the mapping, and doing virtually ANYTHING to a surface mapped surface, destroys the surface mapping completely.

The problem is that I need to mesh these surfaces and export them and their mapping for use in blender, but meshing separate adjacent surfaces usually results in meshes with vertices that do not line up, so to try to avoid that, I join the surfaces, which ensures all the vertices line up properly, but it destroys the surface mapping.

So I have a couple of questions:

  1. How do I apply surface mapping to a surface and then freeze or otherwise preserve that mapping so I can continue to modify the surface.
  2. If that isn’t possible, why does surface mapping even exist in this state? I can’t really see a use for it at all if it only works on unjoined, unmodified surfaces.

Thanks for any help.

1 Like

Hi Keith - what I’d try is, before you start cutting things up, make a copy of your surface and use it as a custom mapping object to apply to the finished pieces.


1 Like

Hi Pascal,
That doesn’t work when you have to join surfaces together. Isn’t there some way I can just freeze the mapping? I have discovered that splitting a surface mapped surface DOES preserve the mapping (At least in SOME instances), but joining them destroys it, and that seems to be the root of my problem. I cannot create all the road surfaces in one shot because some of the mapping around tight corners gets distorted or shifted, so I have to create them as separate objects, but I need them to be 1 contiguous surface when I generate the meshes. It’s a real catch 22 here and I cannot find a way around it.

I really wish there was some way to “convert” surface mapping to planar mapping, I mean, that’s what it really is, it just has the parts stretched into a continuous straight line, and that’s how it’s represented in the UV editor of blender if I export one of my parts and look at it.

I think I’m just going to have to find some other way to do this, because this is almost completely useless. If the surface mapping would generate properly on these totally-not-complex-at-all shapes in the first place I could generate them all in one go as a single surface, but having to generate them separately leaves me with no way to join them into what I actually need. Was really hoping I could use surface mapping here.

Hi Keith - just in case this is what you need - see the attached file - the mapping object was applied after all the trimming and joining was done - it is on its own layer in this file but can be deleted once applied.

MappingMaybe.3dm (394.5 KB)

@Keith1 - V5 now…


1 Like

Hmm, sorry Pascal, I’m on v5, not 6, could you export it for 5, or does it use features only in 6?

I loaded it up, and I can see what it would be useful for, but it just doesn’t apply to my need. Thanks for trying. I’m just going to have to rethink this process.

I’d just like to elucidate what was shared here in a visual manner. Otherwise, only the OP will learn anything back in 2015. I opened @pascal 's .3DM file that was thoughtfully created to help @Keith1 .

I have personally struggled with Join destroying mapping that was set previously, which is why I feel this post is important.

Just as Keith said, proper Surface mapping of a texture is obtuse… and complicated by Solid objects (as we all want to use.)

Study my screenshot below, of Pascal’s file. Only the Custom Object mapping allows you to have your cake and eat it too.

Rhino’s Surface texturing is hard stuff.