Speed of Horizontal/Vertical vs. Parallel/Perpendicular constraints in sketch

[tttinsT5M6Q]

Hi, I have a question about Horizontal/Vertical vs. Parallel/Perpendicular constraints in sketch regarding performance/speed: in situations where Horizontal/Vertical constraints are interchangeable with Parallel/Perpendicular, will Parallel/Perpendicular be slower to compute comparing to Horizontal/Vertical?

I imagine that, for example, if a line is set as Horizontal, then its "angle" (to be honest I do not know how lines are defined in Fusion 360) does not rely on other objects. And if this line is set to be Parallel to another Horizontal line instead, then maybe editing either line will involve solving the Parallel logic chain?

I have this concern because, I often have to wait one or a few seconds during sketch editing (I am not sure whether my sketches are considered complex or not; the machine is an old Intel i7-4770 with 16GB RAM + RTX 2070S). I wonder whether if I replace any Parallel/Perpendicular with Horizontal/Vertical where possible will actually ease the sketch computing?

Besides, if this consideration makes sense, then I think maybe Parallel/Perpendicular suggestions should have lower priorities than Horizontal/Vertical during sketch drawing? Currently it seems Fusion 360 tries to apply constraints in the order of Perpendicular -> Parallel -> Horizontal/Vertical.

Cheers,

[TrippyLighting]

Can you share a model or a screenshot of a sketch ?

IMHO if you are concerned with that stuff, then your sketches are too complex and you spend too much time sketching and too little time modeling.

[tttinsT5M6Q]

Here are some of the relatively complex sketches I am working on, although I think they should be considered simple.

The lags mostly occur when deep into editing after a while.

The whole file is also attached. Because shared parameters are less convenient and updating links from other files takes a few seconds (when offline), I eventually decided to keep all components in one file (and then assembling in another file, as timeline is really too costly).

Cheers,

[jeff_strater · Accepted solution]

to answer the specific question here:  I have not done any measurement, but in theory parallel/perpendicular and horizontal/vertical should be nearly identical, performance-wise.  Vertical/horizontal is actually implemented as a parallel constraint internally.  In the solver, there are two hidden, fixed lines that are created from 0,0 to 1,0 and 0,0 to 0,1.  Horizontal or vertical is just implemented as a parallel constraint to those fixed geometries.

Of course, there could be small differences, but I would not expect anything significant to show up.

As to why your sketches are slow, that may take some time to analyze.  I have not looked at the sample file yet.  But, if it contains any sketch patterns, or mirror/symmetry constraints, those are usually the culprit.  Sometimes if your sketch has lots of tangent constraints, that can slow things down as well.  It all really comes down to something for which you have no visibility - whether the sketch solver tips over into a "numerical" solve mode.  I'm not enough of an expert to know when that happens, but it usually represents more complex constraint systems

Another thing to try is to turn off Profiles in the sketch palette.  Detecting the profiles can take a significant amount of time in a complex sketch.  Just remember to turn them back on before you want to consume the sketch!  We are planning a project later this year to address this problem - perhaps automatically disabling profiles for larger sketches, or computing them in the background, etc.

[tttinsT5M6Q]

Hi Jeff,

Thanks for your reply. I think, for my specific case, the profiles could be the "major mass". Because I also experience lags on cancels of events that appear to have no actual changes to the sketches (e.g., quit/stop drawing another line after drawing a few, or quit editing a dimension while not have changed it). These lags are the most confusing. I will try turning off Profiles now.

Besides, I do have used a lot of symmetry constraints, although I figured maybe I should try to mirror the 3D bodies instead where possible.

About Horizontal vs. Parallel, I was thinking that, the computation of a Horizontal line can just ends at its Parallel hidden axis. On the other hand, if Line A is set Perpendicular to Line B (automatically, when being drawn to link Line B), while Line B is the Mirror of Line C regarding Line D, Line C is set Perpendicular to Line E ... and finally Line Z is set Horizontal, then the computation of Line A will trigger a much longer logical chain, comparing to set Line A Horizontal directly.

Cheers,

[TrippyLighting]

Your sketches are too complicated and should be broken up into several individual sketches.