TurboCAD Forums

The Ultimate Resource for TurboCAD Knowledge

Register
 
Remember to do a search before you ask a question!!!

Workplane on 3D Obtuse Triangle
Read 3215 times
* April 08, 2016, 03:07:16 PM
I have an obtuse triangle drawn as a 3D polygon with each of the three corners at different heights (z=1,2,3 respectfully).  How do I set the workplane on the plane formed by the triangle?

Logged


* April 08, 2016, 03:34:36 PM
#1
WP by 3 points is most reliable in this instance.

Logged


* April 08, 2016, 04:20:48 PM
#2
I've tried WP by 3 points multiple times without success.  I can place the origin on one corner and the x axis on a second corner, but when i attempt to place the y axis on the third corner (which is not 90 degrees from the x axis) it places the y axis in an odd position.  The resulting workplane is not parallel with the plane of the obtuse triangle.

Logged


* April 08, 2016, 04:39:43 PM
#3
I've tried WP by 3 points multiple times without success.  I can place the origin on one corner and the x axis on a second corner, but when i attempt to place the y axis on the third corner (which is not 90 degrees from the x axis) it places the y axis in an odd position.  The resulting workplane is not parallel with the plane of the obtuse triangle.

Yeah, Workplanes axes are 90° to one another.

Logged
Alvin Gregorio
(mostly Residential Architectural 2D; no formal CAD Training; intermittent TurboCAD user since yr. 2000 [ver6.5])
---TurboCAD: V20.2PP(57.0)[as of 3/12/15]; V19DL(54.2); V11.2Pro; Windows-7-Pro/64-bit; Intel-Core-i3 CPU; 2.27ghz; 4GB RAM; Intel HD Graphics (CPU based)


* April 08, 2016, 04:48:25 PM
#4
After many more attempts I finally got the WP by 3 points to work.  Not exactly sure how.  The only snap on is Vertex and the snap flickers between two points.  Choosing one works while the other doesn't.

Just tried it again and cannot recreate the workplane.  There's got to be an easier way.

Logged


* April 08, 2016, 06:21:45 PM
#5
You sound as if you're confusing workplane with coordinate system.  You're trying to align a Cartesian coordinate system, conventionally orthographic by definition, to two sides of a triangle that doesn't have a right-angle corner.  It can't be done.  Three vertices of a triangle can't define anything but a plane, and the first two points that you specify will be the origin and an arbitrary point along the x axis, but the third point won't lie on the y axis unless the included angle of the two sides is 90 degrees.   Obtuse triangles don't have right angle corners.

Logged


* April 08, 2016, 06:45:44 PM
#6
Here's what I did (but there's got to be an easier way):

>Drew the obtuse 3D triangle, with vertices at three different Z values.
>On the World Workplane, drew a 2D triangle right under that.
>Gave this 2D triangle Height, thereby making it a 3D object.
>Used the 3D Boolean Slice Tool on that 2D-to-3D object; using the "Slice by Plane (3 Points)" option; using the 3 points of the first, 3D triangle.
>Set a "Workplane by Facet", selecting the top facet of the now-sliced 2D-to-3D object.

But there's got to be an easier way.

-Alvin

Logged
Alvin Gregorio
(mostly Residential Architectural 2D; no formal CAD Training; intermittent TurboCAD user since yr. 2000 [ver6.5])
---TurboCAD: V20.2PP(57.0)[as of 3/12/15]; V19DL(54.2); V11.2Pro; Windows-7-Pro/64-bit; Intel-Core-i3 CPU; 2.27ghz; 4GB RAM; Intel HD Graphics (CPU based)


* April 08, 2016, 07:31:11 PM
#7
I drew a 3D line from the Middle point (M) of one leg to the Projection point (J) on the base leg. I then used the Workplane by 3 Points tool. The workplane looks lined up to me when viewed with "UCS Plan". The Near point snap could be used in lieu of Middle point.

Logged
John R.

V17—V21, 2015—2019
Designer, Deluxe, (Professional, Expert, Basic), Platinum
RedSDK enabled
Windows 10 Pro (1803), 64-bit


April 09, 2016, 06:39:12 AM
#8
After many more attempts I finally got the WP by 3 points to work.  Not exactly sure how.  The only snap on is Vertex and the snap flickers between two points.  Choosing one works while the other doesn't.

Just tried it again and cannot recreate the workplane.  There's got to be an easier way.
Are you trying to draw something on the triangle?  I don't seem to have a problem placing the workplane on the triangle's surface using three points and draw something on the triangle.

Logged
Clark
TC2015 Platinum


* April 10, 2016, 05:29:01 AM
#9
The culprit appears to be Extended Ortho; it was on while I was attempting Workplane by 3 Points.  By turning it off and simply using Vertex snap, I was able to consistently set the UCS on the obtuse triangle plane.

Alvin: I didn't try your approach because "there's got to be an easier way" prevailed.
John: I tried your approach multiple times without success.  Could have also been related to the Extended Ortho issue.
Clark: Yes, I am drawing something on the plane of the triangle.

Thanks to all who responded.  I'm a longtime TC user (mid-1990's), currently Pro Plat 2015.  I'm a retired software developer of 42 years.  My last gig was developing in-cockpit navigation systems for Boeing/Jeppesen.

Logged


April 10, 2016, 05:45:11 AM
#10
Thanks to all who responded.  I'm a longtime TC user (mid-1990's), currently Pro Plat 2015.  I'm a retired software developer of 42 years.  My last gig was developing in-cockpit navigation systems for Boeing/Jeppesen.

And you did a good job... ;)

Logged
Clark
TC2015 Platinum


* April 10, 2016, 03:47:11 PM
#11
The culprit appears to be Extended Ortho; it was on while I was attempting Workplane by 3 Points.  By turning it off and simply using Vertex snap, I was able to consistently set the UCS on the obtuse triangle plane.

Use SEKEs to override running snaps instead of turning them off and on, in this case by hovering the cursor over the vertex within the snap aperture and pressing V.

Logged