Examples modified by fkmk

fkmk — Sun, 19 Apr 2015 21:03:51 -0000

--- v1
+++ v2
@@ -1,7 +1,7 @@
 #A toy example
 The basic capabilities of SketchTrack can be demonstrated with a simple toy example. The following code is used to draw a small circle.

-*Draw sleepers
+Draw sleepers
 Init 0 0 0

 Straight 60
@@ -16,7 +16,7 @@

 Goto W2.c
 CurveGrade 3 30 r
-Straight 22.8*
+Straight 22.8

 ![](http://up.picr.de/21649164bo.jpg)

Examples modified by fkmk

fkmk — Sun, 19 Apr 2015 21:03:17 -0000

A toy example

The basic capabilities of SketchTrack can be demonstrated with a simple toy example. The following code is used to draw a small circle.

*Draw sleepers
Init 0 0 0

Straight 60
Curve 180 30 r
Point 10 30 3 r W1 a
Straight 40
Point 10 30 3 l W2 b
Curve 180 30 r

Goto W1.c
CurveGrade 3 30 l

Goto W2.c
CurveGrade 3 30 r
Straight 22.8*

This simple layout demonstrates the basic features of SketchTrack. First of all, the drawing mode is set to produce 3D trackwork and the cursor position is initialised to 0. We start with a 60 cm straight, wich is actially the back part of the oval. This is followed by a 180° curve (with a non-realistic radius of 30 cm). Now comes the first point “W1” which is shown below.

All three ends of the point are automatically equipped with labels. We come from the upper right corner, so the point needs to be drawn from the “a” end. Since both points have a length of 10 cm, the straight track in between has to have a length of 40 cm in order to balance the 60 cm straight in the back side.

The second point “W2” can be added now, this time it is drawn from the “b” end. The cursor advances to the “a” end automatically, so the second 180° curve can be drawn right here and the circle is closed.

As it can be seen in the image above, the “W2.c” label has a directection pointing to the right. We can go to this label and add the curve required to be parallel to the main branch again. This is done here with the CurveGrade command, since the point is specified with a grade so we do not have to calculate the angle. When showing the Ruby Console (Window > Ruby Console) in SketchUp, we can also see the angel of the point here when this is of interest.

Now we can go to the opposite end (“W1.c”) and draw the other CurveGrade.
The remaining question is how long the missing connection between the two CurveGrades is. Of course, this can be calculated from the geometry, but it can also be simply measured in SketchUp with the Tape Measure tool.

After inserting the missing straight with 22.8 cm, the toy circle is finished.

Recent changes to Examples

Examples modified by fkmk

Examples modified by fkmk

A toy example