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Some Concepts for Drawing a
Plastic Bottle in 3D
Some images are saved as 4 bit color for fast loading and so may have lost some resolution

Here is a good example of a complex shape that needs to be broken down into basic parts that are formed with:

  • sweep: top and threads
  • extrude: main body except for flat sides
  • surface connect: handle and upper body - between two or more separated lines, circles or polygons
  • surface patch: lines defining 3 or four closed  sides of a surface
  • solid subtract: handle hole and bottom ribs
  • lines extruded into intersecting surfaces and defined with the Draw->Surface Intersection command: handle and upper body, lower and upper shoulder
  • extrude along curve: bottom curved edge
  • solid subtract: rounded boxes arrayed and solid subtracted to form ribbed bottom

You have all the lines in this 2D drawing to exploit into a 3D drawing. Make the 3D drawing a new file and copy or merge each 2D line or profile into it. Keep both files open and us Alt-Tab to toggle back and forth. Use only the main window in the 3D drawing to make this easy. (close the other views, don't just minimize).

 Make some of your complex entities in new files and then load them into place as symbols (exploded if you need to use snap points)

 You can make one vertical half of the 3D bottle and mirror it to make the other half. That would save some repetitious steps!

Don't try to 'shell' the wall thickness unless you are a glutton for punishment. 
The neck could have thickness in the 'sweep'

It would be valuable to layout some centerlines and use those as a framework to place the profiles that you will extrude for the body and sweep for the top. These profiles exist in your 2D drawing.

 You will be using lines from your 2D drawing extruded into intersecting surfaces in horizontal and vertical directions that will then use the' Surface Intersection' Command to define the junctures.

The light blue elliptical extrusion started as a line, not a plane, and is used both to establish the surface intersection lines which you need to do a "surface connect" with the inside profile of the handle and also as a "solid" to subtract from the body section to create the larger hole.

  Define the objects as solids using 'Solid Define' to use the 'solid subtract' and other solid commands

When the light blue extrusion is 'solid subtracted' from the green body it will leave a grid between the two sides of the hole and the whole unit will become a solid. Use solid explode to break it into entities so you can choose and delete the extraneous grids. Draw whole body (upper and lower before you attempt the hole.

Make copies of entities on separate layers or in new files in case you make a mistake you can't undo!

The dark blue lines were found using Draw->Lines->Surface Intersection. They form the lines you need to surface connect to the smaller inner profiles of the handle.

This shows how lines  are extruded into intersecting curved surfaces (green and blue). Also shows a circle "drawn as a line" extruded. The dark lines are the "Surface Intersections"
This is how you will find the complex curves in your bottle. Delete the surfaces and the intersecting lines will remain.

The little shoulders on the bottle will best be done with this process. Find the intersecting lines at the top and bottom of the shoulder, connect the ends and surface patch them.
Also the upper curved sections can be found with intersecting surfaces and then surface patch or surface connect.

This shows curves extruded in two directions that intersect. The command used to get the result at the lower right was "Slice by Curved Surface". 

The curved surface must exceed the limits of the solid being sliced on all sides. Both sides of the solid remain as separate pieces after the operation.

First image shows curves and their orientation in 3D

Second image shows "Surface Patch" which considers all 4 lines.

Inner shape was drawn in 2D and a larger parallel line was made of it. (One corner was trimmed and new radius applied) 

Both lines had several segments and so were selected and combined into single lines. If surface connect skips a section, the line is not a single entity.

In 3D, larger shape was then moved on Z axis and then used "Surface connect" with 100 planes per line and 20 intermediate breaks, still lost some continuity at "L". Use more planes per line for smoother results.
Box is for visual reference.

Threads are formed using
sweep command "W"

Number of Copies
This is the number of times the original shape is replicated. The more copies you make, the smoother the end result appears, but more copies also take longer to shade or edit. For most purposes you will probably want at least 10 copies per revolution (one copy every 36 degrees). The maximum number of copies is 198.

Span Angle
This is the number of degrees the object will sweep about its axis. For a complete, circular extrusion, enter 360°. If you are creating a spiral shape, you can enter more than 360° to achieve more than one revolution. For example, enter 1440 to get four complete revolutions.

Vertical Offset
This is the distance along the axis of rotation that the final copy is from the original. For normal, circular sweeps, this should be set to zero. If a value is used here, DesignCAD draws a spiral-shaped object instead of a circular object.
Slicing a cone with a curved surface starting at the center.
Curve to cut cone Curve extruded

Curve scaled *2 on Z-axis from back corner to extend through solid

Scaled 1.1 X-axis to extend wider than cone (just to illustrate) and surface intersection made for later use

Completed operation showing all entities. Solid explode to remove planes on cut surface then group define or solid define to keep entities together.
Remember that curved surface must extend BEYOND solid for slice by curved surface

Remember to make lines during some operations that you will need for 
surface connect operations. 
Surface connect works with planes, but more predictably with lines.

With other slice commands be sure to select your entity first and choose 'selection only' in command dialog or it will slice everything it intersects in the drawing!

You can extrude along a curve to make the bottom. Make a parallel by distance smaller copy of the bottom profile for the "curve". 

After extruding to the innermost line, make the line a plane for the center. 

Don't offset the parallel line more than the radius of the corners! You can make several successive parallel lines with different extrude profiles following this rule, otherwise there will be gaps. 

Make the bottom edge extrusion and the bottom plane one solid with solid define so you can subtract an array of rounded boxes [also defined as a single solid] from it in a single operation to get the ribbed bottom. 
One way to get a fillet on an oval is to make a sweep of a rounded edge and then scale it from the center, in this case a factor of 3 on the X axis. The fillet will distort proportionate with the scale.