Posted by Chris Harper on December 18, 2000 at 08:59:22:Hi
I need to reconstruct 3D solid models of bones from the hand, wrist and forearm. The data for each bone is in the form of an ascii text file. The file is organised as following sections:
(example at end of message)
1. the first row has two numbers which are: i) the number of vertices and ii) the number of facets contained in the file. For the smaller bones of the wrist there are around 50 vertices per bone.
2. a block of x,y,z co-ordinates that represent the co-ordinates of the facet vertices used in the surface mesh
3. a block that contains the the row numbers in which the x,y,z co-ordinates of the four vertices of quadrilateral facets can be found. i.e. these are pointers to entries in the first block.
4. same as (2) but with just three pointers, for triangular facets.
I could probably just about work out how to automate this process and get the model built up in AutoCAD, but this would take a long time. Also, I'm not sure how I would convert from a surface facetted model to a solid model. So I was wondering if this data is in a format that could just be squirted into a program without any further manipulation.
Any help appreciated, Chris
Below is an example datafile (units in metres, I think) in case anyone fancies a challenge. This should give a 3D model of the Lunate, one of seven small bones in the (right) wrist:
42 48
0.004261 -0.001703 0.007048
0.002826 0.004696 0.007004
0.003122 0.007898 0.001641
0.003263 0.006091 -0.007377
0.001564 0.0021 -0.013089
0.001373 -0.002229 -0.013051
0.004963 -0.002539 -0.006517
0.00389 -0.005518 0.001042
0.00575 0.000954 0.005476
0.005318 0.003624 0.005716
0.004915 0.006044 0.003451
0.006087 0.004093 -0.003166
0.005885 0.002215 -0.006998
0.006504 0.000655 -0.006021
0.006978 -0.000139 -0.003091
0.006891 -0.001473 0.00066
0.006897 0.001917 0.003563
0.006801 0.003035 0.003444
0.006965 0.003506 0.002304
0.007316 0.003033 0.000571
0.007251 0.002019 0.000307
0.007075 0.00094 0.00103
0.007134 0.000763 0.002405
-0.012155 -0.004439 0.005003
-0.011221 0.001353 0.001211
-0.005395 0.005758 0.000901
-0.00429 0.004267 -0.00267
-0.00373 0.000832 -0.004866
-0.002047 -0.002706 -0.007593
-0.0064 -0.006064 -0.00401
-0.009871 -0.008856 0.002006
-0.011567 -0.003583 0.000183
-0.011552 -0.00048 -0.001346
-0.009972 0.000443 -0.003212
-0.008758 0.000516 -0.004444
-0.007727 0.000076 -0.006474
-0.00722 -0.001695 -0.006724
-0.008812 -0.002522 -0.004577
-0.010294 -0.003841 -0.0019
0.007015 0.00134 0.002984
0.007057 0.002069 0.002076
-0.009488 -0.001386 -0.003562
4 16 8 7 15
4 15 7 6 14
4 14 6 5 13
4 13 5 4 12
4 12 4 3 11
4 11 3 2 10
4 10 2 1 9
4 9 1 8 16
4 23 16 15 22
4 22 15 14 21
4 21 14 13 20
4 20 13 12 19
4 19 12 11 18
4 18 11 10 17
4 17 10 9 40
4 40 9 16 23
4 8 31 30 7
4 7 30 29 6
4 6 29 28 5
4 5 28 27 4
4 4 27 26 3
4 3 26 25 2
4 2 25 24 1
4 1 24 31 8
4 31 39 38 30
4 30 38 37 29
4 29 37 36 28
4 28 36 35 27
4 27 35 34 26
4 26 34 33 25
4 25 33 32 24
4 24 32 39 31
3 41 23 22
3 41 22 21
3 41 21 20
3 41 20 19
3 41 19 18
3 41 18 17
3 41 17 40
3 41 40 23
3 38 39 42
3 37 38 42
3 36 37 42
3 35 36 42
3 34 35 42
3 33 34 42
3 32 33 42
3 39 32 42