Author Topic: Fillets and material wrapping  (Read 890 times)

0 Members and 1 Guest are viewing this topic.

Offline geddhedd

Fillets and material wrapping
« on: September 30, 2021, 03:07:42 am »
Hi there,

Does anyone know how to get around this fillet issue and the way materials wrap around them.

I have just updated from Keyshot 7 to 10 and was really excited to try the new real cloth texture, but when applied to something with fillets, it wraps around them in quite a non uniform way. Is there anyway around this? I have always found Keyshot has struggled with traditional fillets. But I could be missing something.

For reference I am an industrial designer, and I model in Solidworks. This happens on models made in Solidworks, and also on the 'add geometry - rounded cube' directly within keyshot.

Would love to hear how people deal with this sort of thing to create nice uniform textures around filleted objects.

I have attached 2 rough images:
One showing real cloth and how it wraps around a rounded cube
One showing a texture map fabric and how it wraps around a rounded cube. Still seems to have issues, but not quite in the same way.

Many thanks

Ged

Offline DriesV

  • Administrator
  • Hero Member
  • *****
  • Posts: 2628
  • Total likes: 81
  • Product Specialist at Luxion
Re: Fillets and material wrapping
« Reply #1 on: September 30, 2021, 06:26:53 am »
Hi Ged,

The RealCloth material requires the model to have proper and sensible UV coordinates.
Typically, NURBS models like those made in SOLIDWORKS don't have a UV layout that works well with RealCloth. For NURBS models, all surface patches will appear to have their own "UV islands". This makes the RealCloth material look disjointed at surface transitions, as you can see on the fillets/rounds of the cube. Furthermore, NURBS modelers tend to produce UV coordinates that are inconsistently sized and scaled, producing a stretched and scaled appearance on some surfaces. For example, notice how the texture on the corner surface is much denser than on the flat sides.

The only way to address this issue, is to unwrap the UV coordinates of the model. Luckily, since KeyShot 9, we provide the 'Unwrap UV' Geometry tool to do exactly that. Unwrapping is like the inverse process of cutting a flat piece of fabric to shape, in order to fully wrap around and cover your geometry.
Here is a Quick Tip on how to use the Unwrap UV tool.

Let me know if that helps.

Dries

Offline geddhedd

Re: Fillets and material wrapping
« Reply #2 on: September 30, 2021, 08:05:38 am »
Hi Dries,

Thanks for the quick reply.

I never realised Solidworks modelled in Nurbs.

From the Quick tip it seems to suggest that I need to split the surfaces, and then apply the materials to each surface seperately. Is that correct?

If that is correct It's probably quicker for me to apply different colours to the different surfaces within solidworks. Then Keyshot will see these as separate. Or am I missing something there?

Still not sure how the UV wrapping would help in the rounded cube scenario. Sounds like I need to do some more investigation.

Thanks for your help so far.

Ged

Offline RRIS

  • Sr. Member
  • ****
  • Posts: 359
  • Total likes: 31
  • Renze Rispens - industrial designer @ npk design
Re: Fillets and material wrapping
« Reply #3 on: October 01, 2021, 12:14:23 am »
No need to split all the surfaces :)

Watch some Keyshot videos on UV unwrapping, like this: https://www.youtube.com/watch?v=Oh4ibAlp9Q4

Unfortunately, UV mapping is something you just have to deal with, no matter what software you work in.

Offline geddhedd

Re: Fillets and material wrapping
« Reply #4 on: October 01, 2021, 02:53:57 am »
Thanks RRIS,

Yes I went through that video yesterday afternoon. UV mapping is very new to me, still trying to get my head around it but getting there and this video helped. I still don't understand why the splitting of surfaces is taking place in keyshot rather than solidworks.

I tried it on a real world example with a section of a headphone headband as attached.

Am I kind of on the right path?

Rather than splitting the surface in Keyshot, I just changed the colour in Solidworks. This feels easier to me than the Split surface tool in kesyhot. I find the split surfaces in Keyshot a bit clunky. But happy to be hear why this may not be the best idea.

My workflow was like this:

STEP 1 - Coloured the surfaces I would like to split. I did this within Solidworks
STEP 2  - Keyshot sees the coloured surfaces as different surface
STEP 3 - Test real cloth on default UV mapping - Really poor effect
STEP 4 - Test real cloth 3D ply on default UV mapping  - Doesn't work as shown
STEP 5 - Go through the UV Mapping tool in Keyshot (This took a few attempts, but think getting a better understanding now)
STEP 6 - Re-tested the real cloth 3D ply on the modified UV Wrapping. Seems to work really well!

PS - In hindsight I think I should of retessalated the surface prior to STEP 5 to make it easier to pick out the points for UV Mapping

Thoughts and comments welcome.

Thanks

Ged


Offline geddhedd

Re: Fillets and material wrapping
« Reply #5 on: October 01, 2021, 03:39:11 am »
Further to the above,

Also modified to include the fillets at the bottom of the band. Only done a rough job to test.

Loving this Real Cloth material though.
« Last Edit: October 01, 2021, 08:31:51 am by geddhedd »