Reply

Does U-V mesh of complex surface works using UV mapping method?

Hello,

 

I got to know that there is something like UV mapping. It puts flat surface(texture) on 3d surface.

for those who dont know:

http://upload.wikimedia.org/wikipedia/commons/thumb/0/04/UVMapping.png/400px-UVMapping.png

 

I also know that when I turn on surface visualisation I can see U-V mesh.

 

Is that U-V mesh created with the rules of UV mapping? In other words: Can any complex surface be converted to flat one so the U-V direction are perpendicular to each other- the surface has then checked pattern(like it happens when UV mapping is used) ?

 

That is important to me because I have a big problem how to efficiently put carbon fiber(checked pattern) on complex surface.

 

Thank you,

6 REPLIES

Re: Does U-V mesh of complex surface works using UV mapping method?

The UV mesh/woven fabric metaphor isn't exact. Yes, all complex CAD surfaces are created from a set of (roughly perpendicular) U and V directions. If the weave you are trying to place on the surface is very loose, you might be able to spread it here and scrunch it up there to make it fit. The looser the weave, the better you can make it fit without a pucker. Chances are, you might have to cut a relief in the fabric if the complex shape has big changes in curvature, and the curvature is in more than one direction.

 

When CAD programs flatten complex surfaces, they don't use the UV mesh to do it. They mesh with much smaller FEA type mesh, which can be 3 or 4 sided, and then the flattening is a series of small changes to a lot of mesh nodes, just like FEA.

 

The UVMap image you show from wikipedia is kind of idealized. The vertical lines actually touch at the poles. This means that the horizontal line at the top is zero length. This is why on the various map projections, geography size is infinitely distorted the closer you get to the poles. So that double ended arrow between a flat square patch and a globe is mostly fantasy. Unless your material is infinitely stretchy.

 

 

 

 

 

 

 

 

 

 

 

 

Not sure if that answers your question. I have the feeling that the answer you need is "it's not that simple". But depending on the surface and the fabric, you might make it work. People obviously make that process happen, but the UV doesn't just automatically line up with your fabric mesh.

Retired Community Manager for Solid Edge. This account is no longer active.

Re: Does U-V mesh of complex surface works using UV mapping method?

Are you trying to create a flat pattern for a carbon fiber part?

 

Are you trying to put a carbon fiber graphic on your cad model?

 

Depending on what you are trying to do the answer will be diffrent.

 

ST7 should give you a good guess at a flat pattern.

 

Solid Edge can put a texture on a surface now. Look at the Styles command. The rendering in ST7 will give prettier results.

 

Re: Does U-V mesh of complex surface works using UV mapping method?

Hello,

 

Simply I had a feeling that UV mapping(which I somewhat could use in SE) presented in this picture:

shows moreless what happen to plain weave composite when put on put on a sphere.

But it does not- I have made an experiment:

Above we can see carbon/kevlar plain weave composite placed on a hemisphere. It touches the surface almost perfectly. In the second picture we can see the fibers intersect each other at a sharp angle- there the wrinkles want to appear.

 

Yes I want first of all to apply such a texture to complex surface the way it behaves in reality- but the real life simulation (e.g. what would be the shape of each wrinkle, wrinkles detection) is not needed- I know SE is not designed for that. I think SE can in some way return the set of these plain weaved fibers on complex surface. And there where a shape of fibers will look strange I know there will be wrinkles.

 

And the second thing (less important)would be to flatten that complex surface of composite to have a template of that so I can cut from fabric.

 

Thank you

 

 

 

Re: Does U-V mesh of complex surface works using UV mapping method?

If you want the mesh to look perfect on the sphere you would have to first distort the flat image of the mesh towards the top and bottom in the same way as a map of the world is distorted towards the north and south poles.

Re: Does U-V mesh of complex surface works using UV mapping method?

It sounds like you really want to know what parts of you model have a curvature that makes the fabric wrinkle. If you can determine that curvature value then the curvature shading tool on the inspection tab will make it easy to get the information you need. It can be set to highlight the areas that have too much curvature.

Re: Does U-V mesh of complex surface works using UV mapping method?

HS,

 

The problem is that I cant determine the value of curvature that will make my fabric wrinkle. It is not that easy.

 

My last idea (thanks to you ) was to render that surface with carbon(or carbon-like texture) so I can see how this fabrics sets on such surface and given that I can evaluate if any wrinkling is possible.

 

But in ERA in material library there's nothing like carbon and I also got to know that I cant download any material (the .lwa file) from the web and that enterprise, which these .lwa files belongs to is not interested in selling me any "carbon files".

 

I think there should be option to use some more popular files than only these .lwa

 

PS: Is SE ST7 already available?