Animation Example

How to create animations using OpenSDraw. Useful ideas about how to configure LDView for this purpose can be found here.

Step 1

Create the lcad file.

(import locate :local)

(def axle1 ()
 (block

  ; Axle 4
  (tb 0 0 -0.5 0 90 0 "3705" "Black")

  ; Gear 8 Tooth
  (tb 0 0 0 0 0 0 "3647" "Dark_Gray")
  
  ))

(def axle2 ()
 (block

  ; Axle 5
  (tb 0 0 0 0 90 0 "32073" "Light_Gray")

  ; Gear 8 Tooth
  (tb 0 0 1 0 0 0 "3647" "Dark_Gray")

  ; Gear 24 Tooth with Single Axle Hole
  (tb 0 0 -1 0 0 0 "3648b" "Dark_Gray")

  ))

(def axle3 ()
 (block

  ; Axle 5
  (tb 0 0 0 0 90 0 "32073" "Light_Gray")

  ; Gear 24 Tooth with Single Axle Hole
  (tb 0 0 1 0 0 0 "3648b" "Dark_Gray")

  ))

(def angle1 (* time-index 5))
(def angle2 (+ 7.5 (/ angle1 3)))
(def angle3 (+ 7.5 (/ angle2 3)))

(translate (list 0 0 (bw -1))
 (rotate (list 0 0 angle1)
  (axle1)))

(translate (list 0 (bw 2) 0)
 (rotate (list 0 0 (- angle2))
  (axle2)))

(translate (list (bw 2) (bw 2) 0)
 (rotate (list 0 0 angle3)
  (axle3)))

Note

time-index is the animation variable. It will count up from 0 in increments of 1.

Note

This is the gears.lcad file in the examples folder.

Step 2

Create a directory to save the .dat files in, change to this directory and generate the dat files.

cd opensdraw/examples
mkdir animate
cd animate
python ../../scripts/lcad_to_ldraw.py ../gears.lcad gears.mpd 100

Note

This will make 100 different versions of the gears.dat file (time-index = 0..99).

Step 3

Generate the png files in the same directory.

python ../../scripts/ldview_render.py ./

Note

Edit the options in ldview_render.py depending on the desired results (point of view, background color, etc..)

Step 4

Create a movie. I find ImageJ be a handy tool for this. You can import the series of .png files as an image sequence (File -> Import -> Image Sequence).

See Also

The belt.lcad example, which demonstrates animating a 3D chain and sprocket system. The chain.lcad example, which demonstrates animating a 2D chain and sprocket system.