Impossible to create sphere in position

[Anonymous]

When I create a sphere it forces me to place the sphere in a new, blank sketch, which is useless because there is no way to reference the things I've already laid out in my sketches.  It only snaps to the blank sketch grid.

I already made a sketch and placed a point where I want the sphere, but it won't let me create a sphere on that point.  I don't understand how this is supposed to work.

Also if I click edit feature, there is no way to select a different initial point for the sphere.

Also I know I can move a sphere after creation using Point to point, but then this doesn't get updated if i alter any sketches parametrically.  Moves are not recorded parametrically.

[chrisplyler]

What SHOULD happen is that they should remove the first four primitives from the menu, so that people will quit using them and then coming into the forum to complain about them. They're useless in a parametric workflow. If you need a sphere you should be using a sketch and a revolve just like you would do for any other round shape.

[J.C.jones]

They could remove it, but a more constructive attitude would be to improve it (e.g. by making these tools parametric) rather than discarding otherwise useful features that do serve a definite purpose. That would also have your desired effect of stopping people from "coming into the forum to complain about them".

[chrisplyler]

That's true, but I wouldn't use them even if they worked right. I prefer to have consistent workflows. Everything else requires sketching and extrudes/revolves/sweeps/etc., so that's what I'm going to be doing most of the time, and if I want a sphere in a certain place I'm just going to continue along with that method.

Using the primitives doesn't involve a sketch. Which makes it harder to relate to other things that DO involve a sketch. If they had another way to parametrically relate them to things, then I would have to practice two different methods for editing those relationships. I might as well just be able to use my sketch and edit everything I want.

[J.C.jones]

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Which makes it harder to relate to other things that DO involve a sketch.

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I can see why this might be true in your workflow, but I do not agree that this statement is universally true. Using projection tools, user parameters or joints I have personally never had difficulty relating non-sketch generated bodies to sketches or vice versa, certainly not more so than if I were to use only sketches. In fact, I would say I rely mostly on sketches as well - certainly for complex designs - but in a few specific instances I found that using a well placed primitive was, or would have been, the more elegant solution.

One would assume that such elementary tools would work at the same basic level as rest of the program, so I was surprised to find that this isn't even a recent bug — it was brought up all the way back in 2015, even responded to by someone from Autodesk (!), yet it remains unfixed to this day.

So again, I would appreciate an update from someone from Autodesk in this thread.

[chrisplyler]

My understanding was that these primitives are the remains of early development, and then once the direction changed to the sketch-and-create methodology, no further development of the primitives was undertaken. If that's true, then I couldn't consider them buggy so much as just never finished. And I'm quite confident that they will NEVER be improved. So really the best solution available, whether you are happy about it or not, is to fully commit to the sketch-and-create paradigm.

We are the Borg. You WILL be assimilated.

[J.C.jones]

Nah I'll stick to primitives, saves time and heartache👍

[etfrench]

Why do you think the primitive sphere isn't parametric?  All of the values necessary to locate it in space and set its size are available when it's jointed to any other geometry.

[J.C.jones]

@etfrenchThat's demonstrated in this post.

[TheCADWhisperer]

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@J.C.jones wrote:

Nah I'll stick to primitives, saves time and heartache👍

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I would disagree and consider this amateur level modeling.

As far as saving time - you would not be able to keep up with my students.

[chrisplyler]

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@etfrench wrote:

Why do you think the primitive sphere isn't parametric?  All of the values necessary to locate it in space and set its size are available when it's jointed to any other geometry.

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The only thing parametric about the sphere is its diameter. And it isn't parametric the way everything else is...via sketch dimensions/constraints. And be honest...it's more of a pain to dig down to a d-value in the parameters list than it is to change a sketch dimension. And those other parameter values are not things that are parametric about the sphere.

I'll take, "Fusion trivia for $300," Alex.

The answer is, "Those other parameter values are...,"

"Things that are parametric about the joint!"

[Ajay_Kumar_Reddy]

Hey I found some hack for doing that.

reference the 3d geometry for positioning and then remove it after creating the sphere.

watch the video to do the same.

[etfrench]

Hmmm... I think the definition of parametric is the ability to change the relevant parameters of an object.  A sphere only has one parameter, its size.  Controlling its location is no more difficult than controlling a sphere created in a sketch and jointed to another object.

[chrisplyler]

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@Ajay_Kumar_Reddy wrote:

Hey I found some hack for doing that.

reference the 3d geometry for positioning and then remove it after creating the sphere.

watch the video to do the same.

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If you make the decision to do that...why wouldn't you just sketch-n-create your sphere the regular way?

[chrisplyler]

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@etfrench wrote:

Hmmm... I think the definition of parametric is the ability to change the relevant parameters of an object.  A sphere only has one parameter, its size. Controlling its location is no more difficult than controlling a sphere created in a sketch and jointed to another object.

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You think it's easier to edit a Joint's offsets than it is to edit a dimension string?

[etfrench]

Editing a dimension in a sketch to change an object's location probably isn't a good idea when the object is positioned with a joint.   If your workflow positions objects using joints, then it's no harder to change the position of a sphere than the position of a sketch created object. 

[liam6N4V6]

How is this issue not fixed yet. Pay a lot for this license.

[etfrench]

What specifically needs to be fixed?  Anyone can create a sphere and position it easily with a joint or a sketch dimension.

[J.C.jones]

The fact that the sphere and other primitive creation tools don't simply snap (and thus parametrically linked after creation) like you would expect and how basically everything else in Fusion 360 does.

[liam6N4V6]

The fact that the sphere and other primitive creation tools don't simply snap (and thus parametrically linked after creation) like you would expect and how basically everything else in Fusion 360 does.

[TrippyLighting]

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@liam6N4V6 wrote:

The fact that the sphere and other primitive creation tools don't simply snap (and thus parametrically linked after creation) like you would expect and how basically everything else in Fusion 360 does.

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I could not agree more and have voiced this a number of times. Actually I have also suggested to either make the primitives fully parametric, or remove them from the menu.

The feedback I received was less than encouraging.

Granted, it's not the most urgent thing and perhaps not the most important. In other 3D modeling applications (not necessarily CAD) primitives are very important and are the first thing users interact with when modeling.