Simplest Example of the calculateProperties Function
This web page describes how to visualize one tetrahedra with the
help of the 3DVDM system. In this example we place the tetrahedra in
the middle of the VR coordinate system. We allow the user to change two
parameters of the visualization: (i) on/off the visualization and (ii)
the size the visualized tetrahedra
Three blocks of code are used to visualize the tetrahedra: (i) the
allocation of the memory (cf. lines 14-24 of the code below), (ii) the
computation of the visualization parameters (cf. lines 25-41), and the
transfer of the data to the VR++ module of the system (cf. line 52).
The rest of the code is required to implement turning on/off of the
visualization. For example, lines 10-41 implements the scenario, when the
showObjects check box of the GUI is selected, and lines 42-51 implements
the scenario, when the showObjects check box is not selected.
It is a good starting point to use selected parts of the following
code to integrate new modules into the 3DVDM system. One should include
copy and paste the allocation of memory part (yellow block), computation
of the visualization parameters part (green block), and the transfer
of data block into your newly created module, and change the lines to
suite your needs.
1 TaskState ExampleMapper::calculateProperties()
2 {
3 float record[3]; // x,y,z of the visualized point
4 unsigned long object; // objectNumber
5 float shape = 1.0; // tetrahedron pointing upwards
6 float rot_x, rot_y, rot_z; // rotation of the object
7 float size_x, size_y, size_z; // the size of the object
8 float color, brightness, opacity; // color, brigh, opa of the object;
9
10 /* If the showObject check box is selected, then we
11 visualize one point in the center */
12 if ( showObjects == true ){
13
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14 /* Allocating memory for one visualization primitive */
15 numberOfObjects = 1; // number of objects visualized
16 if (properties == NULL) {
17 properties = new float[PROPERTIES*numberOfObjects];
18 propertiesBufferSize = numberOfObjects;
19 } else {
20 delete [] properties;
21 properties = new float[PROPERTIES*numberOfObjects];
22 propertiesBufferSize = numberOfObjects;
23 }
24
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25 /* visualization parameters of the tetrahedra in the center */
26 size_x = size_y = size_z = objectSize; // the size of the object comes
27 // from the menu
28 record[0] = record[1] = record[2] = 0.5; // the center point in [0..1]^3
29 rot_x = rot_y = rot_z = 0.0;
30 color = 1.0; // red
31 brightness = 1.0; // super bright
32 opacity = 1.0; // super oparcite
33 object = 0; // Object ID
34
35 // Placing the tetrahedra into the properties variable
36 setObject( object, shape,
37 record[0], record[1], record[2],
38 rot_x, rot_y, rot_z,
39 size_x, size_y, size_z,
40 color, brightness, opacity );
41
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42 } else {
43 /* If the showObjects check box is not selected, we deallocate memory
44 and show nothing */
45 numberOfObjects = 0;
46 if (properties != NULL) {
47 delete [] properties;
48 properties = NULL;
49 }
50 }
51
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