# Trouble drawing a Parabola

**URL:** <https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136>\
**Category:** Modeling Questions\
**Created:** [March 9, 2018, 1:26am UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136 "2018-03-09T01:26:05Z")\
**Posts on this page:** 20\
**Page:** 1

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**Author:** ![TechDragon](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/techdragon/32/1678_2.png) [@TechDragon](https://discourse.shapr3d.com/u/TechDragon)\
**Post date:** [March 9, 2018, 1:26am UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/1 "2018-03-09T01:26:05Z")

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I’m trying to draw a curve that follows a parabola, but the control point interface is proving insufficient. Am I using it wrong?

![image](https://cdck-file-uploads-us1.s3.dualstack.us-west-2.amazonaws.com/flex002/uploads/shapr3d/original/2X/3/30929a53fe2e00727cc0d7b8d6419a06a58d8bb0.jpg)

It’s incredibly frustrating to spend hours tweaking control points over and over and over without making much headway.

For reference the formula of the parabola is y=1.674x^0.66

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**Author:** ![Peter\_Shapr3D](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/peter_shapr3d/32/1271_2.png) [@Peter\_Shapr3D](https://discourse.shapr3d.com/u/Peter_Shapr3D)\
**Post date:** [March 9, 2018, 7:36am UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/2 "2018-03-09T07:36:54Z")

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Hello,

Unfortunately, Shapr3D currently does not support drawing parabolic curves out of the box. With Shapr3D’s spline curve, you can only approximate it by using different number of control points.

Peter

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**Author:** ![TechDragon](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/techdragon/32/1678_2.png) [@TechDragon](https://discourse.shapr3d.com/u/TechDragon)\
**Post date:** [March 9, 2018, 8:03am UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/3 "2018-03-09T08:03:19Z")

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This seems like a major limitation. I wasn’t expecting complex tools to build curves from arbitrary formulas, but I’d be pretty happy with some power user functionality and the ability to switch the type of curve/spline (quadratic, cubic, etc) so that the control points can more easily be used to build basic geometric surfaces like parabolas and hyperbolas.

I mean really if I want a nice organic looking hyperbola surface I shouldn’t need to build it in Blender, use some conversion tools/plugins to export from blender into STEP format, and then import into Shapr3D via iCloud files, because I can’t rely on airdrop, some other CAD viewer app hijacks the airdrop extents or mimetype or however Apple decided iOS would chose which app to open files on the iPad with by default.

All of that in order to continue editing the rest of my design in Shapr3D which is honestly one of the nicest 3D editors I’ve ever used. It really ruins the enjoyment I’ve had being able to work on the go, enjoying the ease of input using the Apple Pencil.

Is this kind of functionality likely to be part of the upcoming improvements to curve editing? Or is that going to focus on other aspects of the curve editing experience?

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**Author:** ![Peter\_Shapr3D](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/peter_shapr3d/32/1271_2.png) [@Peter\_Shapr3D](https://discourse.shapr3d.com/u/Peter_Shapr3D)\
**Post date:** [May 13, 2018, 5:23pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/4 "2018-05-13T17:23:13Z")

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Improving curve editing is not on our very short roadmap at the moment.

Best,

Peter

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**Author:** ![WCL](https://avatars.discourse-cdn.com/v4/letter/w/74df32/32.png) [@WCL](https://discourse.shapr3d.com/u/WCL)\
**Post date:** [September 15, 2020, 7:02am UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/5 "2020-09-15T07:02:29Z")

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I too am trying to model a part which most of it is completed however I need to add a very exact radius of 84 deg between two planes. To create a type of bowl. How would I do this? My job is actually depending on this. I purchased this for my company with people believing in the my advice to buy this yearly fee.

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**Author:** ![WCL](https://avatars.discourse-cdn.com/v4/letter/w/74df32/32.png) [@WCL](https://discourse.shapr3d.com/u/WCL)\
**Post date:** [September 15, 2020, 7:04am UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/6 "2020-09-15T07:04:45Z")

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I really have to agree with the gentleman above. Like why is that not one of your first priorities? Everything else seems so beautifully well thought out. It’s a real issue. And if I look like a loser I’m going to have a meltdown brother.

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**Author:** ![WCL](https://avatars.discourse-cdn.com/v4/letter/w/74df32/32.png) [@WCL](https://discourse.shapr3d.com/u/WCL)\
**Post date:** [September 15, 2020, 7:12am UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/7 "2020-09-15T07:12:08Z")

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Please see retardi diagram.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/0/056ebf257e68838023cc1bdddca16a5ea5fd1fd0.jpeg)

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**Author:** ![Oregonerd](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/oregonerd/32/8012_2.png) [@Oregonerd](https://discourse.shapr3d.com/u/Oregonerd)\
**Post date:** [September 15, 2020, 12:43pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/8 "2020-09-15T12:43:41Z")

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Can you hand sketch a profile of you parabole please. rather the actual part you are trying to create. How exact must it be to the parabole shown in the first image?

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**Author:** ![Oregonerd](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/oregonerd/32/8012_2.png) [@Oregonerd](https://discourse.shapr3d.com/u/Oregonerd)\
**Post date:** [September 15, 2020, 1:04pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/9 "2020-09-15T13:04:08Z")

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Switch your spline type to “control”. I was able to nearly perfectly reproduce that parabole profile using the spline. What kind of accuracy do you need?

(I’d send a screen shot but it’s too early for this PC guy to learn how to screen shot an iPad \<= I’ll have enough coffee in me in 1 hour, maybe)

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**Author:** ![Oregonerd](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/oregonerd/32/8012_2.png) [@Oregonerd](https://discourse.shapr3d.com/u/Oregonerd)\
**Post date:** [September 15, 2020, 1:07pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/10 "2020-09-15T13:07:04Z")

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Disclaimer: I am/was a vector art guru using Corel Draw to create instructions, illustrations and what not.

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<div class="post-metadata">

**Author:** ![Oregonerd](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/oregonerd/32/8012_2.png) [@Oregonerd](https://discourse.shapr3d.com/u/Oregonerd)\
**Post date:** [September 15, 2020, 2:57pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/11 "2020-09-15T14:57:12Z")

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![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/a/a931d2846b401e21142842db18a54295280c5a98.jpeg)

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**Author:** ![WCL](https://avatars.discourse-cdn.com/v4/letter/w/74df32/32.png) [@WCL](https://discourse.shapr3d.com/u/WCL)\
**Post date:** [September 15, 2020, 3:46pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/12 "2020-09-15T15:46:25Z")

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\*\* Can you hand sketch a profile of you parabole please. rather the actual part you are trying to create. How exact must it be to the parabole shown in the first image?

Basically the width of the top of the parabola is exact at 223mm in the drawling. The width of the bottom of the parabola is exact at 130mm in the drawing and the height is exact at 70mm is all in the drawling. Those are the parts of the drawling that are done.

All that is left is if you look at the contour of the dish the side walls are straight, as in without radius. Much like a pan for gold. That is not what I need. I need that wall of the pan to have a radius to it. Like a bowl. The radius must be 84mm @ 52 deg.

I have attached a hand drawling.

I really appreciate your reply,and help with this

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/4/4871cad7dc240a73151a4e5256abc609b5ecb1f4.jpeg)

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<div class="post-metadata">

**Author:** ![WCL](https://avatars.discourse-cdn.com/v4/letter/w/74df32/32.png) [@WCL](https://discourse.shapr3d.com/u/WCL)\
**Post date:** [September 15, 2020, 3:50pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/13 "2020-09-15T15:50:11Z")

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Basically I will be using this drawling to convert to a car file for production. So it needs to be precise. I am still learning this program and so very newbie here. I almost have no experience in this field as is.

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**Author:** ![Robert](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/robert/32/1329_2.png) [@Robert](https://discourse.shapr3d.com/u/Robert)\
**Post date:** [September 15, 2020, 4:17pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/14 "2020-09-15T16:17:07Z")

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[dog bowl.shapr](https://discourse.shapr3d.com/uploads/short-url/i16jypFSpKjQFOMoVKq3XaOo1ku.shapr) (6.0 MB)

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<div class="post-metadata">

**Author:** ![WCL](https://avatars.discourse-cdn.com/v4/letter/w/74df32/32.png) [@WCL](https://discourse.shapr3d.com/u/WCL)\
**Post date:** [September 15, 2020, 4:49pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/15 "2020-09-15T16:49:46Z")

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Amazing sir. I really really appreciate this. The fact that you just finished it for me is really incredible.

Can I ask how you went about drawling the arch?

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**Author:** ![Robert](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/robert/32/1329_2.png) [@Robert](https://discourse.shapr3d.com/u/Robert)\
**Post date:** [September 15, 2020, 5:02pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/16 "2020-09-15T17:02:56Z")

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![bild](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/f/f71c5a60d919bac94195459171397cdb8956b08b.jpeg)

Just draw a arc between the two lines and set the values  
Revolve from the centerline then use the shell tool

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<div class="post-metadata">

**Author:** ![WCL](https://avatars.discourse-cdn.com/v4/letter/w/74df32/32.png) [@WCL](https://discourse.shapr3d.com/u/WCL)\
**Post date:** [September 15, 2020, 5:49pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/17 "2020-09-15T17:49:23Z")

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So this is where I am at. I don’t understand revolve from the center line.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/9/98e248fa6e96c080a47b1f8294d69521281b11af.png)

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**Author:** ![JasonJessica](https://avatars.discourse-cdn.com/v4/letter/j/dc4da7/32.png) [@JasonJessica](https://discourse.shapr3d.com/u/JasonJessica)\
**Post date:** [September 15, 2020, 5:50pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/18 "2020-09-15T17:50:59Z")

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@WCL Revolve your shape around the Z axis “centerline”.

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**Author:** ![McD](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/mcd/32/15504_2.png) [@McD](https://discourse.shapr3d.com/u/McD)\
**Post date:** [September 15, 2020, 6:19pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/19 "2020-09-15T18:19:33Z")

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> **[iCloud.com](https://www.icloud.com/photos/#0FVwSA7slOifUNz_04MutkDIQ)**

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<div class="post-metadata">

**Author:** ![McD](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/mcd/32/15504_2.png) [@McD](https://discourse.shapr3d.com/u/McD)\
**Post date:** [September 15, 2020, 6:22pm UTC](https://discourse.shapr3d.com/t/trouble-drawing-a-parabola/2136/20 "2020-09-15T18:22:35Z")

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Here’s a better video with the pen and touch points turned on.

> **[iCloud.com](https://www.icloud.com/photos/#0ZNoL8makMi4vhh3RVLPSnL6w)**

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