Why does Fusion 360 still not support mirroring 3D sketches in 2024, while both Solidworks and Inventor can?

[huanghaowna]

For example, when creating an Iron Man helmet, I need to place anchor points using a 3D sketch. Since the middle is a continuous curved surface, using a mirror on one side of the solid to create the other side results in the middle connection becoming sharp and unnatural. Although I’ve found some tricks from others to achieve mirroring (first mirror, then project the 3D object), it’s still somewhat cumbersome, especially compared to what I’ve seen with Solidworks and Inventor, where they can directly mirror points in the 3D sketch to create the other side’s 3D anchor points.

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[johnsonshiue]

Hi! As far as I am aware, Inventor does not support mirroring 3D sketch geometry within 3D Sketch environment either. To have a symmetric sketch, the user needs to derive the part or the assembly and enable Mirror option.

Edited: Inventor 3D Sketch does support associative Mirror. Any 3D sketch geometry can be mirrored within 3D Sketch environment.

Many thanks!

[TrippyLighting]

The answer is likely because different modeling techniques not involving 3D sketches can achieve the same thing 😉

[huanghaowna]

Using Forms or polygon modelling is indeed a method used by many people, and it also comes with mirror function. I just prefer the precision of NURBS modeling.

[huanghaowna]

Which version are you using? I tried the 2024 version yesterday, following someone's video instructions. After creating a new part and a 3D sketch, I just placed points, used 3D Transform, and Mirrored them directly then patch them，without setting up any assemblies or anything.

[TrippyLighting]

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@huanghaowna wrote:

Using Forms or polygon modelling is indeed a method used by many people, and it also comes with mirror function. I just prefer the precision of NURBS modeling.

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I was not talking about form/T-Splines. I am talking about surface modeling techniques.

Using 3D sketches as shown in the video is just not a good idea in Fusion. There are no real 3D constraints.

Fr example in a 2D sketch in Fusion you can a horizontal constraint and it is unambiguous what that does.

In a 3D sketch, it is horizontal to what plane? Doe "horizontal even make sense in a 3D sketch with an arbitrary coordinate system?

[johnsonshiue]

Hi @huanghaowna,

I was wrong. I am very sorry that I misspoke. Indeed, Inventor does support Mirror within 3D Sketch. It was achieved by using the symmetric constraint in 3D.

Many thanks!

[huanghaowna]

Anyway, thanks for your kind help！😁

[huanghaowna]

Could you elaborate on how you would operate if it were you? Do you mean to achieve this modeling based on the reference image purely using 2D sketches? Would this require the continuous construction of many planes or sketches? Additionally, can't this be considered as using the reference image's front view and right view as reference planes?

[TrippyLighting]

Could you share the file you have so far?

Yes, I would mostly work with 2D sketches.

[johnsonshiue]

Hi! Regarding the alternative workflows to "mirror" 3D curves in Fusion, one may consider leveraging surface bodies. You may create a surface body using the curves on one side. Next, you may mirror the body. Then include the edges on the mirrored body as the mirrored curves.

Many thanks!

[huanghaowna]

This is how I initially learned from others: in the front view, I first used mirroring at each position point to get the points on both sides, and then moved them in the right view. Then the two sides no longer automatically symmetrized. This method might also lead to the situation where if one side's points are accidentally moved, they would no longer be symmetrical, and it would be difficult to notice.So I wanted to find another method that could ensure I only need to work on one side, with the other side always being symmetrical in the most convenient way.

[huanghaowna]

Are you referring to the operation similar to the video I initially sent?

(Creating a single-sided surface with Patch, mirroring to get the other side, then creating a new sketch and using Project —— "Include 3D geometry" to get the points and edges on the other side, modifying the middle connection line on both sides to make it a curve, connecting the left and right sides, and then generating a new complete surface)

The result of this operation indeed achieves the effect I wanted.

[johnsonshiue]

Hi! There are multiple ways to create a surface body from a 3D curve. You may also use Ruled Surface command (Direction) to protrude the curve as a surface body.

Many thanks!