help: FORM Convert dont show body

[lomi043]

using CONVERT on form doesn't show the body and no errors showed too. need advice

thanks in advance

[TheCADWhisperer]

@lomi043 

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

[lomi043]

here is the file, ty

[TrippyLighting · Accepted solution]

As a beginner you should turn on the timeline.

Here are some T-Spline guidelines:

1. Model 80% in box view mode. The shape should somewhat resemble the desired, smooth end result. Make small adjustments in smooth-view mode. Check back in box view mode to make sure the model still has integrity. Faces should not intersect in box view mode!

2. Do not add detail until you are 100% satisfied with the overall shape and proportions of the shape. The more detail you add the more geometry you have to manipulate, usually resulting in a lot more work than necessary.

3. Avoid triangles at all cost until you are at least at an intermediate level with T-Spline modeling. Triangles are best avoided altogether.

4. Limit the use of N-gons (polygons with more than 4 edges/vertices) to the bare minimum. No N-gons with more than 5 edges vertices. 

5. Start with as little geometry as you can get away with. Add more as needed. If you find that you need to stretch polygons too much to get a desired smooth shape, then you need more edge loops/polygons.

[lomi043]

thanks for the tips,  i always turned off timeline to save resources on my pc, but my prob right now is ive been able to convert this without error yet no solid body is showing, it just toggles the visibility on the t spline model

[TrippyLighting]

I've added edges where needed to get to a quad-only model and also removed all the creases. I also improved the edge flow some. Now it converts.

I recommend not modeling with applied creases. If you need creases, then apply them when you're done modeling.

[laughingcreek]

As @TrippyLighting has demonstrated, the t-spline had edge flow issues that needed to be addresses. 

As a separate issue, there is also a bug here.  the t-spline was in error, so it wouldn't convert.  the bug would be that it doesn't tell you it's in error, it just doesn't convert. @Phil.E ?

[phil_eichmiller]

Agreed.

I bet the form is actually succeeding, which is why there is no error. The bug happens after that, and produces a null body. Not enough to error, not enough to produce a b-rep body. The data literally falls thru the crack here. The good news is this isn't common, at least IMO. I've never seen it before that I can recall. The tspline team is pretty responsive. I'll let you know what they find.

[laughingcreek]

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@phil_eichmiller wrote:

Agreed.

I bet the form is actually succeeding, which is why there is no error. The bug happens after that,....

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the form is in error from the beginning.  this is a topology error that can only be cleared by correcting the edge flow.  these types of t-spline errors are extremally difficult to explain to people with little experience.   

[adam.helps]

@laughingcreek is correct--this surface has problems. Using "repair body" to fix it is the right way to get a good result.

However, failing to display an error message during conversion is a bug. The topology here confused the underlying T-spline kernel and it did something stupid. We're working on it.

Even with that fix, though, the solution suggested by @laughingcreek is the correct one. It's better to solve the topology issue. The corner in the top of that face makes it look like it's trying to be a pentagon, but that was canceled out by an L-point at the bottom (L-points are rarely good). I'd suggest splitting that face up (the insert point tool should work) and getting rid of the L-point.

[glenn-chun]

The bug against not showing any error has been fixed in Fusion version 2.0.18220 released on January 29, 2024.