Fill tool error: Invalid body generated

[Fengqi_Song]

When I was reproducing this shampoo-bottle-like model using the Fill tool, the software kept giving me an ‘Invalid body generated’ error. I know this error usually appears when a body with zero thickness is created, but I can’t see where the problem is in my model. I’d really appreciate it if you could help me analyze this. Thank you so much.

I’ve attached my source file and a screen recording of the process for reference.

model2.shapr (45.7 KB)

[Xdrakosha]

Strange…

[Fengqi_Song]

What? It works on your device? That’s so strange.

[Xdrakosha]

@Fengqi_Song

It works on your device?

Could be that I have a newer version with some fixes…

[ShaprGligDav]

Hello Guys,
Yes, we have fixed that error despite the preview exists BUG, and it is out for the public.
Please update your Shapr3D to the latest available version, and yell at me if the issue is still there

[Fengqi_Song]

The issue was indeed caused by the software version, as you mentioned. However, a new problem has appeared. After updating to the latest version, there are no error alerts anymore. Still, the outer edge cannot achieve G1 or G2 transitions as shown in the demo video — it only results in a sharp G0 transition. Could you help me check if this is a problem with my model or an ongoing software bug?

[Fengqi_Song]

Hi, the software update resolved the error message. However, I’m still unable to generate G1 or G2 transitions as demonstrated in the official demo video.

[Xdrakosha]

@Fengqi_Song

it only results in a sharp G0 transition

This is the correct behavior. To use tangency with a guide curve, you first need to make sure the curve is tangent to the other geometry.

Try it without the guide curve and enable tangency. You’ll see what shape the guide curve needs to have.

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Here is the result after I corrected guide curve

[markse]

I think this was you were going after sharp transition. Just g2 in the middle, you can cut that and mirror it.

[Fengqi_Song]

You’re right. But if you watch the official demo video, you’ll see that G1 or G2 transitions can be achieved in their demonstration without strictly following this rule.

Create a Curved Soap Bottle Surface | Shapr3D Fill Tool

[Fengqi_Song]

This is indeed a valid workaround.

[Xdrakosha]

@Fengqi_Song

But if you watch the official demo video

It works in the project from the demo video because their curve has the appropriate shape.

When I said you needed to make the curve tangent, I was referring to the tangency at the edges, not in the center.

[markse]

Not sure if thats a full demo but, it doesn’t show how the curve was made which results in user trying to replicate and connect with G2 instead only G0 would work. So basically video didn’t show steps before Fill Tool and how the curves was drawn.

[jean-philippe2]

Hi,
If we only put the bottom of the curve in tangent and put the continuity level only on the bottom and on the curve (3xG1), the result is there, right?

![Capture d’écran 2026-10-29 à 19.44.21|481x500]

[jean-philippe2]

with a small fillet along the edge…

[Fengqi_Song]

Alright, I totally understand now. Following your advice, I re‑constrained the end control points to maintain tangency at the transition, and it worked out great. Appreciate your patient guidance!

[Fengqi_Song]

Thank you for the thorough explanation. It helped me gain a deeper understanding of the principles and rules behind this. Following your advice, I successfully reproduced this case. Thanks again!

[Fengqi_Song]

Yeah, that made me overlook the key principles behind it. Looks like I need more practice to build a better understanding of the underlying theory.