1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
|
/*************************************************************************
* *
* Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. *
* All rights reserved. Email: russ@q12.org Web: www.q12.org *
* *
* This library is free software; you can redistribute it and/or *
* modify it under the terms of EITHER: *
* (1) The GNU Lesser General Public License as published by the Free *
* Software Foundation; either version 2.1 of the License, or (at *
* your option) any later version. The text of the GNU Lesser *
* General Public License is included with this library in the *
* file LICENSE.TXT. *
* (2) The BSD-style license that is included with this library in *
* the file LICENSE-BSD.TXT. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files *
* LICENSE.TXT and LICENSE-BSD.TXT for more details. *
* *
*************************************************************************/
/*
This demo shows how to use dContactMotionN in a lifting platform.
*/
//#include <unistd.h> // for usleep()
#include <ode/ode.h>
#include <drawstuff/drawstuff.h>
#include "texturepath.h"
#ifdef _MSC_VER
#pragma warning(disable:4244 4305) // for VC++, no precision loss complaints
#endif
// select correct drawing functions
#ifdef dDOUBLE
#define dsDrawBox dsDrawBoxD
#define dsDrawSphere dsDrawSphereD
#define dsDrawCylinder dsDrawCylinderD
#define dsDrawCapsule dsDrawCapsuleD
#define dsDrawConvex dsDrawConvexD
#endif
// some constants
#define NUM 100 // max number of objects
#define DENSITY (5.0) // density of all objects
#define GPB 3 // maximum number of geometries per body
#define MAX_CONTACTS 8 // maximum number of contact points per body
#define USE_GEOM_OFFSET 1
// dynamics and collision objects
struct MyObject {
dBodyID body; // the body
dGeomID geom[GPB]; // geometries representing this body
};
static int num=0; // number of objects in simulation
static int nextobj=0; // next object to recycle if num==NUM
static dWorldID world;
static dSpaceID space;
static MyObject obj[NUM];
static dJointGroupID contactgroup;
static int show_aabb = 0; // show geom AABBs?
static int show_contacts = 0; // show contact points?
static int random_pos = 1; // drop objects from random position?
static int write_world = 0;
static int show_body = 0;
static dGeomID platform, ground;
dVector3 platpos = {0, 0, 0};
int mov_type = 2;
dReal mov_time = 0;
const dReal mov1_speed = 0.2;
dVector3 mov2_vel = { 0.2, 0.1, 0.25};
/****************************************************************
* Movement 1: move platform up, reset every 80 units of time. *
* This is the simplest case *
****************************************************************/
static void moveplat_1(dReal stepsize)
{
mov_time += stepsize;
if (mov_time > 80)
mov_time = 0;
platpos[0] = platpos[1] = 0;
// the platform moves up (Z) at constant speed: mov1_speed
platpos[2] = mov1_speed * mov_time;
}
// Generate contact info for movement 1
static void contactplat_1(dContact &contact)
{
contact.surface.mode |= dContactMotionN;
contact.surface.motionN = mov1_speed;
}
/****************************************************************
* Movement 2: move platform along direction mov2_vel, reset *
* every 80 units of time. *
* This is the most general case: the geom moves along *
* an arbitrary direction. *
****************************************************************/
static void moveplat_2(dReal stepsize)
{
mov_time += stepsize;
if (mov_time > 80)
mov_time = 0;
// the platform moves at constant speed: mov2_speed
platpos[0] = mov2_vel[0] * mov_time;
platpos[1] = mov2_vel[1] * mov_time;
platpos[2] = mov2_vel[2] * mov_time;
}
// Generate contact info for movement 1
static void contactplat_2(dContact &contact)
{
/*
For arbitrary contact directions we need to project the moving
geom's velocity against the contact normal and fdir1, fdir2
(obtained with dPlaneSpace()). Assuming moving geom=g2
(so the contact joint is in the moving geom's reference frame):
motion1 = dCalcVectorDot3(fdir1, vel);
motion2 = dCalcVectorDot3(fdir2, vel);
motionN = dCalcVectorDot3(normal, vel);
For geom=g1 just negate motionN and motion2. fdir1 is an arbitrary
vector, so there's no need to negate motion1.
*/
contact.surface.mode |=
dContactMotionN | // velocity along normal
dContactMotion1 | dContactMotion2 | // and along the contact plane
dContactFDir1; // don't forget to set the direction 1
// This is a convenience function: given a vector, it finds other 2 perpendicular vectors
dVector3 motiondir1, motiondir2;
dPlaneSpace(contact.geom.normal, motiondir1, motiondir2);
for (int i=0; i<3; ++i)
contact.fdir1[i] = motiondir1[i];
dReal inv = 1;
if (contact.geom.g1 == platform)
inv = -1;
contact.surface.motion1 = dCalcVectorDot3(mov2_vel, motiondir1);
contact.surface.motion2 = inv * dCalcVectorDot3(mov2_vel, motiondir2);
contact.surface.motionN = inv * dCalcVectorDot3(mov2_vel, contact.geom.normal);
}
static void nearCallback (void *, dGeomID o1, dGeomID o2)
{
dMatrix3 RI;
static const dReal ss[3] = {0.02,0.02,0.02};
dContact contact[MAX_CONTACTS];
int numc = dCollide (o1, o2, MAX_CONTACTS,
&contact[0].geom, sizeof(dContact));
if (numc)
dRSetIdentity(RI);
bool isplatform = (o1 == platform) || (o2 == platform);
for (int i=0; i< numc; i++) {
contact[i].surface.mode = dContactBounce;
contact[i].surface.mu = 1;
contact[i].surface.bounce = 0.25;
contact[i].surface.bounce_vel = 0.01;
if (isplatform) {
switch (mov_type) {
case 1:
contactplat_1(contact[i]);
break;
case 2:
contactplat_2(contact[i]);
break;
}
}
dJointID c = dJointCreateContact (world,contactgroup,contact+i);
dJointAttach (c, dGeomGetBody(o1), dGeomGetBody(o2));
if (show_contacts)
dsDrawBox (contact[i].geom.pos, RI, ss);
}
}
// start simulation - set viewpoint
static float xyz[3] = {2.1106f,-1.3007,2.f};
static float hpr[3] = {150.f,-13.5000f,0.0000f};
static void start()
{
//dAllocateODEDataForThread(dAllocateMaskAll);
dsSetViewpoint (xyz,hpr);
printf ("To drop another object, press:\n");
printf (" b for box.\n");
printf (" s for sphere.\n");
printf (" c for capsule.\n");
printf (" y for cylinder.\n");
printf ("Press m to change the movement type\n");
printf ("Press space to reset the platform\n");
printf ("To toggle showing the geom AABBs, press a.\n");
printf ("To toggle showing the contact points, press t.\n");
printf ("To toggle dropping from random position/orientation, press r.\n");
printf ("To save the current state to 'state.dif', press 1.\n");
}
char locase (char c)
{
if (c >= 'A' && c <= 'Z') return c - ('a'-'A');
else return c;
}
// called when a key pressed
static void command (int cmd)
{
dsizeint i;
int k;
dReal sides[3];
dMass m;
int setBody;
cmd = locase (cmd);
if (cmd == 'b' || cmd == 's' || cmd == 'c' || cmd == 'y')
{
setBody = 0;
if (num < NUM) {
i = num;
num++;
}
else {
i = nextobj;
nextobj++;
if (nextobj >= num) nextobj = 0;
// destroy the body and geoms for slot i
if (obj[i].body) {
dBodyDestroy (obj[i].body);
}
for (k=0; k < GPB; k++) {
if (obj[i].geom[k]) {
dGeomDestroy (obj[i].geom[k]);
}
}
memset (&obj[i],0,sizeof(obj[i]));
}
obj[i].body = dBodyCreate (world);
for (k=0; k<3; k++) sides[k] = dRandReal()*0.5+0.1;
dMatrix3 R;
if (random_pos)
{
dBodySetPosition (obj[i].body,
dRandReal()*2-1 + platpos[0],
dRandReal()*2-1 + platpos[1],
dRandReal()+2 + platpos[2]);
dRFromAxisAndAngle (R,dRandReal()*2.0-1.0,dRandReal()*2.0-1.0,
dRandReal()*2.0-1.0,dRandReal()*10.0-5.0);
}
else
{
dBodySetPosition (obj[i].body,
platpos[0],
platpos[1],
platpos[2]+2);
dRSetIdentity (R);
}
dBodySetRotation (obj[i].body,R);
dBodySetData (obj[i].body,(void*) i);
if (cmd == 'b') {
dMassSetBox (&m,DENSITY,sides[0],sides[1],sides[2]);
obj[i].geom[0] = dCreateBox (space,sides[0],sides[1],sides[2]);
}
else if (cmd == 'c') {
sides[0] *= 0.5;
dMassSetCapsule (&m,DENSITY,3,sides[0],sides[1]);
obj[i].geom[0] = dCreateCapsule (space,sides[0],sides[1]);
}
else if (cmd == 'y') {
dMassSetCylinder (&m,DENSITY,3,sides[0],sides[1]);
obj[i].geom[0] = dCreateCylinder (space,sides[0],sides[1]);
}
else if (cmd == 's') {
sides[0] *= 0.5;
dMassSetSphere (&m,DENSITY,sides[0]);
obj[i].geom[0] = dCreateSphere (space,sides[0]);
}
if (!setBody)
for (k=0; k < GPB; k++) {
if (obj[i].geom[k]) {
dGeomSetBody (obj[i].geom[k],obj[i].body);
}
}
dBodySetMass (obj[i].body,&m);
}
else if (cmd == 'a') {
show_aabb ^= 1;
}
else if (cmd == 't') {
show_contacts ^= 1;
}
else if (cmd == 'r') {
random_pos ^= 1;
}
else if (cmd == '1') {
write_world = 1;
}
else if (cmd == ' ') {
mov_time = 0;
}
else if (cmd == 'm') {
mov_type = mov_type==1 ? 2 : 1;
mov_time = 0;
}
}
// draw a geom
void drawGeom (dGeomID g, const dReal *pos, const dReal *R, int show_aabb)
{
int i;
if (!g) return;
if (!pos) pos = dGeomGetPosition (g);
if (!R) R = dGeomGetRotation (g);
int type = dGeomGetClass (g);
if (type == dBoxClass) {
dVector3 sides;
dGeomBoxGetLengths (g,sides);
dsDrawBox (pos,R,sides);
}
else if (type == dSphereClass) {
dsDrawSphere (pos,R,dGeomSphereGetRadius (g));
}
else if (type == dCapsuleClass) {
dReal radius,length;
dGeomCapsuleGetParams (g,&radius,&length);
dsDrawCapsule (pos,R,length,radius);
}
else if (type == dCylinderClass) {
dReal radius,length;
dGeomCylinderGetParams (g,&radius,&length);
dsDrawCylinder (pos,R,length,radius);
}
if (show_body) {
dBodyID body = dGeomGetBody(g);
if (body) {
const dReal *bodypos = dBodyGetPosition (body);
const dReal *bodyr = dBodyGetRotation (body);
dReal bodySides[3] = { 0.1, 0.1, 0.1 };
dsSetColorAlpha(0,1,0,1);
dsDrawBox(bodypos,bodyr,bodySides);
}
}
if (show_aabb) {
// draw the bounding box for this geom
dReal aabb[6];
dGeomGetAABB (g,aabb);
dVector3 bbpos;
for (i=0; i<3; i++) bbpos[i] = 0.5*(aabb[i*2] + aabb[i*2+1]);
dVector3 bbsides;
for (i=0; i<3; i++) bbsides[i] = aabb[i*2+1] - aabb[i*2];
dMatrix3 RI;
dRSetIdentity (RI);
dsSetColorAlpha (1,0,0,0.5);
dsDrawBox (bbpos,RI,bbsides);
}
}
// simulation loop
static void updatecam()
{
xyz[0] = platpos[0] + 3.3;
xyz[1] = platpos[1] - 1.8;
xyz[2] = platpos[2] + 2;
dsSetViewpoint (xyz, hpr);
}
static void simLoop (int pause)
{
const dReal stepsize = 0.02;
dsSetColor (0,0,2);
dSpaceCollide (space,0,&nearCallback);
if (!pause) {
if (mov_type == 1)
moveplat_1(stepsize);
else
moveplat_2(stepsize);
dGeomSetPosition(platform, platpos[0], platpos[1], platpos[2]);
updatecam();
dWorldQuickStep (world,stepsize);
//dWorldStep (world,stepsize);
}
if (write_world) {
FILE *f = fopen ("state.dif","wt");
if (f) {
dWorldExportDIF (world,f,"X");
fclose (f);
}
write_world = 0;
}
// remove all contact joints
dJointGroupEmpty (contactgroup);
dsSetColor (1,1,0);
dsSetTexture (DS_WOOD);
for (int i=0; i<num; i++) {
for (int j=0; j < GPB; j++) {
if (! dBodyIsEnabled (obj[i].body)) {
dsSetColor (1,0.8,0);
}
else {
dsSetColor (1,1,0);
}
drawGeom (obj[i].geom[j],0,0,show_aabb);
}
}
dsSetColor (1,0,0);
drawGeom (platform,0,0,show_aabb);
//usleep(5000);
}
int main (int argc, char **argv)
{
// setup pointers to drawstuff callback functions
dsFunctions fn;
fn.version = DS_VERSION;
fn.start = &start;
fn.step = &simLoop;
fn.command = &command;
fn.stop = 0;
fn.path_to_textures = DRAWSTUFF_TEXTURE_PATH;
// create world
dInitODE();
world = dWorldCreate();
#if 1
space = dHashSpaceCreate (0);
#elif 0
dVector3 center = {0,0,0}, extents = { 100, 100, 100};
space = dQuadTreeSpaceCreate(0, center, extents, 5);
#elif 0
space = dSweepAndPruneSpaceCreate (0, dSAP_AXES_XYZ);
#else
space = dSimpleSpaceCreate(0);
#endif
contactgroup = dJointGroupCreate (0);
dWorldSetGravity (world,0,0,-0.5);
dWorldSetCFM (world,1e-5);
dWorldSetLinearDamping(world, 0.00001);
dWorldSetAngularDamping(world, 0.005);
dWorldSetMaxAngularSpeed(world, 200);
dWorldSetContactSurfaceLayer (world,0.001);
ground = dCreatePlane (space,0,0,1,0);
memset (obj,0,sizeof(obj));
// create lift platform
platform = dCreateBox(space, 4, 4, 1);
dGeomSetCategoryBits(ground, 1ul);
dGeomSetCategoryBits(platform, 2ul);
dGeomSetCollideBits(ground, ~2ul);
dGeomSetCollideBits(platform, ~1ul);
// run simulation
dsSimulationLoop (argc,argv,352,288,&fn);
dJointGroupDestroy (contactgroup);
dSpaceDestroy (space);
dWorldDestroy (world);
dCloseODE();
return 0;
}
// Local Variables:
// c-basic-offset:4
// End:
|