Rhino tutorial: Creating 2D Objects

In this tutorial the basics of 2D drawing will be explained. These 2D objects will be the basis of 3D objects in other tutorials.

Drawing Curves

Creating polylines

We will start a model as a basis for a water tower. As the tower is round and symmetric you will only draw one half of the tower.

1. Start a new model File > New... and choose Large Objects - Meters
   
   
2. Make viewport Front active by clicking in the viewport.
   To prevent strange behaviour toggle SmartTrack (STrack) off
   
   
3. Create a polyline Curve > Polyline > Polyline and for the start of the polyline type 6,0 (absolute x,y)
   
   
4. For the next point type @5,0 (relative x,y)
   
   
5. For the next point type @-1,20 (relative x,y)
   
   
6. For the next point type @2,2 (relative x,y)
   
   
7. For the next point type <45 (constraint angle) then type 9 (constraint distance) and finally click somewhere above the last point in the Front viewport
   
   
8. For the next point type @-0.5,0 (relative x,y)
   
   
9. For the next point type @0,-1.5 (relative x,y)
   
   
10. For the next point type @-4,0 (relative x,y)
    
    
11. For the next point type @0,3 (relative x,y)
    
    
12. For the next point type @-1.5,0 (relative x,y) and press Enter or space to end the command

Save this file. We will use it in tutorial Creating 3D Objects.

To make it 3D we can use the revolve command Surface > Revolve (see tutorial Creating 3D Objects).</br>

Drawing arcs

In the menu bar click on Panels and then select Tutorials, a pop up window will appear. Click on the arrow left of Level 1 tutorials and then select Arc1.3dm. Rhino will download this file from the website of McNeel.

Drawing a center, start, end or angle arc

1. Toggle Osnap on and choose only End, Cen and Tan as persistent snap.
2. From the menu click Curve > Arc > Center, Start, Angle
   
   
3. For the Center snap to the center of the circle at the lower left
   
   
4. For the Start snap to the end of the line
   
   
5. For the End snap to the end of the other line

Drawing a start, end, direction arc

1. From the menu click Curve > Arc > Start, End, Direction
   
   
2. For the Start snap to the end of the upper end of the vertical line
   
   
3. For the End snap to the left end of the upper horizontal line
   
   
4. Toggle Ortho on and click above the start point for the tangent at the start point

Make another Direction Arc at the upper right

1. From the menu click Curve > Arc > Start, End, Direction
   
   
2. For the Start snap to the end of the right end of the horizontal line
   
   
3. For the End point type @2,-2 and press Enter
   
   
4. With Ortho on click under the start point for the tangent at the start point

Adding more arc segments using extension option

1. From the menu click Curve > Arc > Center, Start, Angle
   
   
2. Click Extension on the command line
   
   
3. For the curve to extend, click on the end of the arc you just made
   
   
4. For the End of the arc type 4 (constraint distance) and press Enter
   
   
5. With Ortho on click below the first point
   The arc will be tangent to the curve you chose
   
   
   
6. From the menu click Curve > Arc > Center, Start, Angle
   
   
7. Click Extension on the command line
   
   
8. For the curve to extend, click on the end of the arc you just made
   
   
9. For the End of the arc snap to the end of lower horizontal line

Drawing a tangent, tangent, radius arc

1. From the menu click Curve > Arc > Tangent, Tangent, Radius
   
   
2. For the First tangent curve click on the lower right side of the upper circle
   
   
3. For the Second tangent curve click on the upper right side of the lower circle
   
   
4. For the Radius type 3 and press Enter
   
   
5. Move your cursor and click when the correct arc is displayed
   
   
   
6. From the menu click Curve > Arc > Tangent, Tangent, Radius
   
   
7. For the First tangent curve click on the upper left side of the upper circle
   
   
8. For the Second tangent curve click on the lower left side of the lower circle
   
   
9. For the Radius type 6 and press Enter
   
   
10. Move your cursor and click when the correct arc is displayed

Making an arched slot

1. Select the two arcs you just created
   
   
2. From the menu click Edit > Trim
   
   
3. For the object to trim click on the inner edge of each circle
   Now you will be left with a slot

Save this file. We will use it in tutorial Creating 3D Objects.

To make it 3D we can use the extrude command Solid > Extrude Planar Curve > Straight (see tutorial Creating 3D Objects).

• This chapter is taken from Rhinoceros Level 1 Traning Manual v4.0 (Febr 2008). Robert McNeel & Associates.