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Can we have a sketch conic?

mark_biasottimark_biasotti Member Posts: 123 ✭✭✭
edited November 2014 in Product Feedback
I have a project that current requires a sketch conic  as the basis of the main feature. Is it poisible to have a sketch conic in Onshape?

P.S. Now that SW has them I use them all the time. I refer to them as a poor-man's spline but that is not a fair discription because they are so much more than that. I mention this because for introduction into a new MCAD machine design product they really should come BEFORE splines.

I fought like hell for 10 years to get them into SW - hopefully I don't have to do that again with OS :-)

Mark
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Comments

  • caradoncaradon OS Professional, Mentor Posts: 300 PRO
  • lougallolougallo Member, Moderator, Onshape Employees, Developers Posts: 1,839
    @mbiasotti‌ Currently conics in OS is in the fillet command only but this is a perfect thing to request via the feedback option in OS.  I will ticket it from here for you... and @DriesV‌
    Lou Gallo / PD/UX - Support - Community / Onshape, Inc.
  • andy_morrisandy_morris Moderator, Onshape Employees Posts: 87
    Let me ask more philosophical questions:  Is it important for you to have style curves only in a sketches?
    Or, are there situations where having separate curve features outside of a sketch would be more beneficial?
    Andy Morris / Head of Product Design / Onshape, Inc.
  • mark_biasottimark_biasotti Member Posts: 123 ✭✭✭
    edited November 2014
    Is it important for you to have style curves only in a sketches?

    Yes, but of course, if they can be both 2D and 3D sketches and if they provide everything a 2D or 3D curve feature can do.  ProE and NX (as did many others) took the route of having distinct curve features (as did SW in the early days) but in the end, they are not as versatile as a sketch curve, because of the constraints and dimensioning that you can apply to them. In 2D it is useful to have the spline as a sketch element because you and seamlessly combine them with other sketch geometries; if it were it's own curve feature, you could not do that (so easily.) As a point of reference, SW 3D sketch spline and Style spline are MUCH more versatile than the ProE curves because of the D-cubed contains (2D) and the dimensioning that you can apply to them, not to mention the built-in sketch environment familiarity that is inherent to them vs. having to learn a 3D curve feature. The downside is the non D-cubed 3D constraint solver in SW which make them very unreliable and buggy - Ask Dave C. about that... :-)
  • kevin_quigleykevin_quigley Member Posts: 306 ✭✭✭
    Andy, CV splines like Rhino...2D and 3D...with ability to apply contraints to adjacent curves and surfaces. And conic curves and surfaces. Onshape has an opportunity here to put tools like these inhe hands of everyone. Frankly, the thing that naffs me off about so called MCAD systems is the excuse used " machine designers don't need splines"... No.
  • caradoncaradon OS Professional, Mentor Posts: 300 PRO
    edited November 2014
    I would go so far as to say: throw away the good ol' 'engineering' 3 degree B-spline (as currently in Onshape probably).
    In SolidWorks, the new Style Spline is FAR better than the legacy spline in terms of controling curvature and quality (of curves and surfaces). In any surface modeler (Rhino, Alias...), if you're serious about the quality of surfaces, you NEVER build surfaces from B-splines. ALWAYS use CV-controlled single-span curves. I think an important part of Onshape should be about teaching best practices. Single-span curves as input for surface creation is an excellent example of that...

    Simply provide only best-in-class tools. Position Bezier curves as the default 'style curve'. I will allow you to add B-spline too, but only for cosmetic wires and stuff. :D
    I've witnessed too many horrible abuses of B-splines...

    Dries
  • andy_morrisandy_morris Moderator, Onshape Employees Posts: 87
    This is great feedback, thanks. 

    What we wanted to achieve for pre-production was a simple spline that could be used by machine designers for cable runs, hence we implemented the current splines that can have fixed length.

    What we want to achieve for styling purposes needs to be different and right first time. So I'm hearing CV curves, including conics, are essential. So are well-behaved 3D curves that you can easily and efficiently manipulate and constrain to adjacent geometries. I also get that to create profiles you need awesome curves in the sketch.

    If we provided powerful curve features outside of a sketch, would that be acceptable too?

    Andy 

    Andy Morris / Head of Product Design / Onshape, Inc.
  • caradoncaradon OS Professional, Mentor Posts: 300 PRO
    edited November 2014
    @AndyMorris‌
    "If we provided powerful curve features outside of a sketch, would that be acceptable too?"
    My own experience with 'curve features' is limited to SolidWorks. Are you talking about projected curves, helix, split lines etc.?
    Obviously those type of curves are needed. Oh, and iso curves...

    Dries
  • kevin_quigleykevin_quigley Member Posts: 306 ✭✭✭
    Andy, I never use any form of projected or composite curve apart from split lines. The reason is simple. Once a curve is a composite it has no control over the number of CVs, and no control for editing. I'm not exactly following what you mean about curves outside sketches? Frankly I don't care if a curve resides in or out a sketch as long as I can edit the CVs and any associated geometry derived from that sketch can be updated through that sketch edit.

    If you want to see some great examples of associating outside sketch curves check out Shark FX or Ashlar-vellum Cobalt. The core interface to these apps has not really changed since the early 90s - we are taking full 3D curve creation and editing in 3D space. Rhino does much the same now but the interface is not as good and the downstream associativity is limited to one feature. Shark and Cobalt have full associativity.

    Another one to check is SolidThinking. again the interface is a rather clunky but it has more surfacing tools and constraints than either Shark or Cobalt, again with full associativity. Frankly SolidThinking is a better product than Rhino but it is very underused outside Italy and France.
  • kevin_quigleykevin_quigley Member Posts: 306 ✭✭✭
    Andy, one more thing. If the primary function of the spline tool now is to provide fixed length wiring, then please include a pipe tool. By this I mean, draw your curve (or select lines/arcs in sketch etc) then "make pipe" - choose your OD and ID, maybe even start OD and end OD and BOOM, pipe. I have been asking for this in SolidWorks for years (yes I know Routing has something like it but it is not the same, and a lot of extra cost for a pipe tool). In the meantime we struggle on with sketch>spline>plane at end of spline>sketch>circles>sweep...zzzzzzzz...zzzzz
  • caradoncaradon OS Professional, Mentor Posts: 300 PRO
    edited November 2014
    @KevinQuigley‌
    Great points.

    I agree that Onshape should focus on 'clean' curve creation tools. That's why I much prefer Beziers (SW Style Spline) over B-Splines (legacy Spline). In my book too, curve-on-curve projections are a big no, UNLESS Onshape provides (awesome) Class-A curve and surface tools for reparametrization. A GREAT example of this is the Autodesk Shape Modeling Plug-in for Rhino (which I use and find seriously awesome). It has a very powerful and quite intuitive set of tools for high-end surfaces. Some of the things it can do: reparametrize projected curve to a single-span curve of given degree (with tolerance evaluation), fit an untrimmed surface onto a trimmed surface, 4-sided surface matching, CV pulling of surfaces while maintaining continuity at boundary etc. Some people say it is more powerful than ICEM Surf...

    Great suggestion about the pipe tool. This is exactly what (I think) Onshape needs: design-centric tools, not just CAD operators. Like Kevin suggests, it could be automated 'macros' of laborious/cumbersome/repetitive tasks.

    Dries
  • mark_biasottimark_biasotti Member Posts: 123 ✭✭✭
    [email protected]

    SolidWorks, the new Style Spline is FAR better than the legacy spline in terms of controling curvature and quality 

    Thanks - one of my last projects I initiated and worked on with my colleague Rob Jost.... We fought hard to get that over many years. Nice to hear you like it.

    Mark
  • pete_yodispete_yodis OS Professional, Mentor Posts: 666 ✭✭✭
    @mbiasotti Reminds me of this quote....

    “Don't worry about people stealing your ideas. If your ideas are any good, you'll have to ram them down people's throats.” - Howard Aiken, IBM engineer

  • Nickolas_LockardNickolas_Lockard OS Professional Posts: 29 ✭✭
    Subscribed to thread. I need precisely defined conics daily for my work. (correct focus, directrix, arclength and chord length for my packaging analysis and for setup of process lines as well as optical analysis of reflective parabolic surface. I have a giant camera to capture optical deviations, but would like to analyze surface deformations in simulations. PS: I'm new to modeling, so I don't always follow the discussions well, but trying my best. Thanks for a good thread.
  • Nickolas_LockardNickolas_Lockard OS Professional Posts: 29 ✭✭
    How about use/project of a bitmapped image file? I imported BMP and have correct parabola shape from excel plot. Now can I project/use it somehow to create sketch lines or surface which I can thicken into a part? Really struggling with this, and really need some kind of solution. Plotting dots and making splines is not working adequately. I need the shape accurate to +/- 0.15 mm along an ~1900 mm arc.
  • lougallolougallo Member, Moderator, Onshape Employees, Developers Posts: 1,839
    @nick_lockard Projecting off of a raster image is probably not going to be the greatest solution.  I have seen plenty of tools that will find the color differential and try to "trace" the part.  How did you acquire the raster? 
    Lou Gallo / PD/UX - Support - Community / Onshape, Inc.
  • Nickolas_LockardNickolas_Lockard OS Professional Posts: 29 ✭✭
    @lougallo I built equation in Excel, plotted, fitted curve (R^2 = 1), and saved as bitmap image. Resolution isn't great. I think equation-driven parabola sketches would be best. Just need something now.
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