automatically projected geometry

[Anonymous]

I am not sure if I grasp the concept of Fusion in when and how geometry is automatically projected - or not. It seems to be totally arbitrary to me.

Here is a screencast of one example. There are multiple sketches on top of each other. Each one has an other functionality, I am using them as layers.

There is a construction sketch, some lines for orientation of the construction of the different parts.

You see me drawing a new sketch using some of the sektches as reference.

My question are:

- at 0:34 the line tool stops drawing a line (noticed when hiding the reference sketch at 0:47. Why?

- after 1:00 you see me checking the lines for projected geometries. Some lines are, some not. Why?

- why did it project one of the lines from the "construction" sketch? the user (me) has no control over this behavior.

- what it the idea behind automatically projected lines? I mean why does it make sense to have two identical lines on top of each other?

- why are there in addition to the lines points projected?

- why would I have to break the link before I can delete the lines and points? If I want to delete I obviously want to brake the link.

- at 3:40 you see that there is one last point that even though the link was removed, still is displayed red. I think this is a display error. There is no obvious way to remove that last point from the sketch.

- at the very end you see the grid appear without any user command. I verified after the recording: the checkbox was still unchecked....

In the next screencast you see me removing that last dot:

- why do I have to assign the coincident property twice? For each adjacent line once? What is the concept behind this?

Screencast2

If you think of the simple task I am trying to achieve, draw a simple, independent sketch on top of an other, don't you think it is a bit complicated and too steps are involved? Or is there any other way that I don't know about? It could be, I am still learning...

Regards

Leo

[Anonymous]

Hi Leo, unfortunately at the moment I don't have enough time to go through all your questions, but first let me say that in general the sketching process in Fusion 360 is somewhat different than other softwares (from what I've heard).  The ideal workflow is to first "roughly" create your geometry in a sketch, then get everything aligned and sized as desired by adding constraints and dimensions.  You can test degrees of freedom by trying to move stuff around.   

The first thing I would try doing to possibly clear up some confusion, is while in/editing a sketch, insure up to only one additional sketch is visible.  For one thing, that insures you know which other sketch is being projected into current sketch (note projected geometry means when a projected geometry moves/changes, the projection (purple) will also update accordingly). Otherwise it may very well be arbitrary which of the multiple visible superimposed sketches is going to get projected. 

When you were "tracing" that other sketch (or I should say sketches 😉 ), I noticed the line tool terminated at one point, hence not creating a complete closed shape.  You'll know if the line tool terminated when there are not any angles or dimensions shown in real time, which normally appear as a new line is about to be made. 

I've never had to Break Link to delete projected geometry, only if I needed to move it. 

That was very observant of you to note a coincident constraint was absent in that corner by indication of the white point.  The easiest way to do that is left mouse button press and hold on that point until the selection list comes up, then select one of the two Sketch Points in the list.  Then go over to the sketch pallete and choose Coincident constraint.  Then go back over to the point, click and hold again then select the other Sketch Point in the list, and the coincident should be made between the two line endpoints. 

Once you get a little more familiar with Fusion 360 it's a great experience in general!

Jesse

[jiang_peng]

Hi Leo,

It's bit hard to understand the problems only via the video. Could you please attach the file or send it to me? My email is: Jiang.Peng@autodesk.com

thanks

[jiang_peng]

From the video, my idea is there is no auto-projected line created. But there are several auto-projected points created.

[jeff_strater]

Hi, and thanks for posting this.  It's a good topic, and your questions are valid.  Thanks for providing the screencasts - that is a huge help.

Rather than address the details of your screencasts, let me step back a bit and try to explain the "theory" of automatic projected geometry, and maybe that will help you understand some of what you are seeing.  Please feel free to respond - this is a complicated topic, and we are very interested in feedback exactly such as this.  A dialog would be great.  I don't at all claim that we have it right, and we welcome suggestions to improve Fusion.

There are two kinds of automatic projection that Fusion does.  The first is when you sketch on a model face.  We automatically project the edges of that face into the sketch.  We don't, by default, draw those projected curve, mostly to reduce visual clutter, but they are there.  But, I think that is not your main area of interest.

The second kind of automatic projection is the one in your first screencast.  In this workflow, while you are drawing new sketch geometry, only if your view is directly down at the sketch, then, Fusion will automatically infer and project geometry into your sketch.  This is really intended for a workflow like this:

so, when you look straight down on your sketch, you see:

So, while you are sketching, if you go over one of those lower edges, and it will be auto-projected:

Now, this style of autoproject works on any geometry that can be projected.  So, in your case, it is the other sketches (your "layers").  The same workflow applies.  So, if your cursor is over a sketch element in another sketch, that will be projected into the active sketch.  In your case, these sketches are all on the same plane, which definitely confuses everything, but in reality, it is exactly the same.

The final piece of the puzzle is:  Fusion attempts to not project the same entity twice.  But, if you have lines, for instance, in the same place on different sketches, those are different entities.  So, it is certainly possible to autoproject overlapping (even identical) geometry.  For instance:

These are 3 sketches on different planes, but with the similar geometry.  Looking down on the new sketch, it looks like this:

and you can see that I have projected all 3 of the vertical lines into the sketch.

So, hopefully that clears up some of your questions.

Final personal opinion comment:  All of this is why I do not like or use autoproject.  I much prefer to manually project geometry into my sketches, so I know exactly what reference I am going to get.  Unfortunately (for me), there is no way to disable this, other than rotating the view.  So, I end up rotating the view when I am sketching.  It takes some getting used to, I'll admit, but to me, it's worth it.

Jeff Strater (Fusion development)

[Anonymous]

Hi Jeff,

thank you very much for your explanations! It was exactly was I was looking for, an explanation about the concept of automatic projection, when it happens and why. I was sure it was developed intentionally and not a flaw. But I just did not understand it. And did not like it and it was driving me mad.

The most valuable tip you gave was that autoprojection does not happen if you turn the sketch.

I completely agree with you that autoprojection does not make sense:

1. it is not intuitive - and I think you want a intuitive application.

2. if one wants a projection you can do it with sketch->project

3. autoproject leads to multiple lines on top of each other which leads to problems later on

4. if you are drawing along some geometry you already have a line that refers to that geometry, why would you want an additional autoproject reference

5. you have no control over autoproject -> unless a feature does help you achieve something it mostly leads to irritations if you have not control over it

6. if it does not autoproject on turned sketches, why should it if you are looking directly down?

7. I did not find sufficient documentation on it

8. Sketches is (manly) 2D, like drawing on a peace of paper. You can see through, you can reference from other object but it should behave 2D. If you start having lines from 3D Objects multiple layers deep under your sketch the 3D is starting to mix in too much, I think. 

wishlist:

- no autoprojection, just sketch->project if you need it

- or give the user full control over this feature

- if you can't live without, at least make it easy to filter-select them and delete.

So, I gave you something that you can throw in (user experience) when you to back you opinion the next time you discuss the development of autoprojection in your team

I filed a request.

Regards 

Leo

[HughesTooling]

Hi Jeff,

Something I'd like to request is the ability to have all projected lines made construction geometry. Maybe a tick box on the sketch dialog or even a setting in properties, 90% of the time I have to change the projected curves to construction curves and it's a real time waster.

I made a request for this on the idaestation last year but it was with other requests, perhaps I should have made on just for this.

http://forums.autodesk.com/t5/fusion-360-ideastation-request-a/better-constraints-and-dimensions/idi...

Thanks Mark.

[jeff_strater]

I agree with this suggestion.  What we have been discussing is relatively simple.  Today, in the sketch palette there is a button to convert the selected curve to construction.  That button should behave like the "bold" button in Word:  If something is selected, it is a conversion action, and if nothing is selected, it is a forward creation setting.  So, all new geometry would be construction if this button was pressed, including new projected geometry.

Jeff

[Anonymous]

I think Mark's idea is very good. Make all projected lines construction lines by default. That would be a solution right in the middle of no autoprojection and autoprojection like it es today.

The user would still have no control, but it would be acceptable I think. I still would ask myself why something gets autoprojected when I can pull it from the geometry with the sketch command when I need it.... 

[HughesTooling]

I find auto projection useful when adding constrains and dimensions. For dimensions I try to use end points of curves then only a point is projected so you get a bit less clutter. When adding constraint like perpendicular or coincident you always get a line that needs changing to construction so some way to have those lines created as construction lines will make Fusion easier to use.

Mark.

[Anonymous]

Hi Jeff,

when I delete a sketch curve that utilized automatically projected geometry,  the automatically projected geometry is still there (in purple). Is there a button to "refresh"/"update" the sketch so that projected geometry no longer in use is removed from the sketch (to reduce clutter). Thank you!

David

[jeff_strater]

Hi @Anonymous,

No, unfortunately, there is no automatic way to "clean up" unreferenced projected geometry.  The only way is to select the projected (purple) geometry and delete them

Jeff

[Anonymous]

Hi Jeff,

I will continue deleting them, then.

I noticed that when I long left press the mouse button to select a sketch point, the fact that all sketch points are in the same place means i can't preview which one I would be selecting. Is there another way to select points that lets me preview which one I'd be deleting or dragging away. I find that 50% of the time I end up dragging the wrong sketch line away.

Excellent product, by the way. I've been using Fusion 360 now for about 160 hrs and I'm very happy with it.

David

[Anonymous]

Second that sentiment.  I completly understand the frustration of autoproject for new(er) users. but I also wouldn't give it up.  When 1/modeling time = $$$$, little things like not have to project lines as a seperate key sequence add up to the difference between keeping a gig and getting beat by someone who is just a little faster.  A turn it off radio button in preferences would be harmless though.  Of course, saving about $6k over solidworks helps too : )

[TrippyLighting]

[daniel_lyall]

that was easy thanks @TrippyLighting

[Anonymous]

Oh, Uhm,  yeah, like that.  I haven't looked in there in a long while.

[Anonymous]

Hi Jeff,

I found a different workflow that works better for me. I am no longer using automatically projected geometry to position new sketch profiles. Instead I am using sketch dimensions. It's easy to see which sketch entities they refer to, and they are easy to select if I want to delete them.

David

[Anonymous]

I found all of the above discussion valuable! Thank you to all the contributors! Some extremely useful tips!