Crease Edge in TSplines results in Box model?

[cekuhnen]

So I select an Edge apply the crease command and the complete model is in box mode ?!

What am I doing wrong here?

[deyop]

Anytime you try to crease an edge that ends in a star point it will change the model into box mode.  It doesn't know how to resolve a smooth shape from it.  It is a limitation in the T-Splines currently.  We have people working on a solution to the problem.  Another way to address the problem would be to add edges in the vicinity of the edge which don't end in a star point.  This will give you some control of the shape in that area.

[cekuhnen]

Hi Deyop,

thanks for pointing this out. I was not aware of that creasing with star points currently do not work. I assumed creasing was working in general.

In addition to the current dev is it possible to have different level of creasing? Currently it looks Fusion only supports full or no crease!

Adding extra loop cuts of course also works just makes the mesh often so much more denser.

Pixar released their last code for subduvision surfaces to the public and it allows perfect edge creasing without the need of extra loopcuts to prevent edge crease artifacts.

Best

Claas

[colin.smith]

Hi Class,

You are correct that we currently only have options for full creasing  or no creasing.  In an upcoming release we will have levels of creasing to choose from.

Cheers,

Colin

[tom.finnigan]

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@cekuhnen wrote:

Pixar released their last code for subduvision surfaces to the public and it allows perfect edge creasing without the need of extra loopcuts to prevent edge crease artifacts.

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Hi Claas,

So I have taken a look at the pixar method for semi-sharp creasing, and it looks like it is unfortunately not directly applicable.  Specifically, using their method is great for rendering to the screen, but if you were to directly convert it to a NURBS then it would subdivide many times near the semi-sharp creases, doing more and more the tighter the radius is.  This is kind of a blocker for us, since we assume that pretty much every T-spline will eventually be converted to NURBS.

We might be able to approximate the surface near the creases so we don't have so many small patches, or come up with another semi-sharp scheme that is more NURBS-friendly.. either way, it is more complex than just dropping in the OpenSubdiv code, unfortunately.

This is not to say that we have given up on creasing - we know it is a high priority, and something that the t-splines team is working on.

- Tom

[cekuhnen]

Hello Tom,

that is too bad. The way how I worked around this was  in my 3D application to bake the model into a finer polygon mesh so the density better reflects the individually creased edges. This worked sufficiently in many cases.

Right with T-Spline in Fusion adding more loopcuts can of course also work. It makes the mesh more denser but it works.

[deyop]

Another way to manage the amount of creasing is to modify the tangent handles that are added whenever a crease is applied to edges.  Here is an video describing the concept.

Managing the tangent handle position will allow you to vary the angle between the two sides of the creased edge which will vary the sharpness of the crease.

[cekuhnen]

@colin.smith

Hey what happened to crease weights?

4 years past 😉

[SaeedHamza]

@cekuhnen

Wow, was there really such a limitation ... strange 😕

Anyway I guess it has been solved at some point, because it's working fine with me

Regards

[SaeedHamza]

This post is ANCIENT!

Post of the first men in Fusion

[cekuhnen]

@SaeedHamza

Yes that works - I pinged Colin to know what happened about selective edge creasing.

T-Splines currently only offers no or full crease.

[SaeedHamza]

I see. That concept of the handles for a crease would be great to have

[cekuhnen]

yeah hence my question about what happened

this is 4 years back

[cekuhnen]

yeah hence my question about what happened

this is 4 years back