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1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
2<html><head><meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
3<title>Open Dynamics Engine: World</title>
4<link href="doxygen.css" rel="stylesheet" type="text/css">
5<link href="tabs.css" rel="stylesheet" type="text/css">
6</head><body>
7<!-- Generated by Doxygen 1.5.3 -->
8<div class="tabs">
9  <ul>
10    <li><a href="index.html"><span>Main&nbsp;Page</span></a></li>
11    <li><a href="modules.html"><span>Modules</span></a></li>
12    <li><a href="annotated.html"><span>Data&nbsp;Structures</span></a></li>
13    <li><a href="files.html"><span>Files</span></a></li>
14  </ul>
15</div>
16<h1>World</h1><table border="0" cellpadding="0" cellspacing="0">
17<tr><td></td></tr>
18<tr><td colspan="2"><br><h2>Functions</h2></td></tr>
19<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API dWorldID&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g929067266d630fb745f752042d685fc7">dWorldCreate</a> (void)</td></tr>
20
21<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Create a new, empty world and return its ID number.  <a href="#g929067266d630fb745f752042d685fc7"></a><br></td></tr>
22<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g5a2e5b1d2d6a1376dca239b488e629f9">dWorldDestroy</a> (dWorldID world)</td></tr>
23
24<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Destroy a world and everything in it.  <a href="#g5a2e5b1d2d6a1376dca239b488e629f9"></a><br></td></tr>
25<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#ga1b220b922215b335572c699cf8f8cad">dWorldSetGravity</a> (dWorldID, dReal x, dReal y, dReal z)</td></tr>
26
27<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Set the world's global gravity vector.  <a href="#ga1b220b922215b335572c699cf8f8cad"></a><br></td></tr>
28<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="ge1a29b6a91cc1910a982c916ae4dee4a"></a><!-- doxytag: member="world::dWorldGetGravity" ref="ge1a29b6a91cc1910a982c916ae4dee4a" args="(dWorldID, dVector3 gravity)" -->
29ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#ge1a29b6a91cc1910a982c916ae4dee4a">dWorldGetGravity</a> (dWorldID, dVector3 gravity)</td></tr>
30
31<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get the gravity vector for a given world. <br></td></tr>
32<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#gacd0778bdaa939d22f093fc2d5d5f868">dWorldSetERP</a> (dWorldID, dReal erp)</td></tr>
33
34<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Set the global ERP value, that controls how much error correction is performed in each time step.  <a href="#gacd0778bdaa939d22f093fc2d5d5f868"></a><br></td></tr>
35<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API dReal&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g033cd87a0b22889a94d4d84149bda5a0">dWorldGetERP</a> (dWorldID)</td></tr>
36
37<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get the error reduction parameter.  <a href="#g033cd87a0b22889a94d4d84149bda5a0"></a><br></td></tr>
38<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g8b7913fe46d0afc468418c655da79233">dWorldSetCFM</a> (dWorldID, dReal cfm)</td></tr>
39
40<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Set the global CFM (constraint force mixing) value.  <a href="#g8b7913fe46d0afc468418c655da79233"></a><br></td></tr>
41<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API dReal&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#gc7a431f2b3fc6f887fe91ad676828ba3">dWorldGetCFM</a> (dWorldID)</td></tr>
42
43<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get the constraint force mixing value.  <a href="#gc7a431f2b3fc6f887fe91ad676828ba3"></a><br></td></tr>
44<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g8f547ebeb3deed27e0f7b8143d475f50">dWorldStep</a> (dWorldID, dReal stepsize)</td></tr>
45
46<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Step the world.  <a href="#g8f547ebeb3deed27e0f7b8143d475f50"></a><br></td></tr>
47<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#ga9c564b4dd7d8fa4c6f4b32dd95fc33a">dWorldImpulseToForce</a> (dWorldID, dReal stepsize, dReal ix, dReal iy, dReal iz, dVector3 force)</td></tr>
48
49<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Converts an impulse to a force.  <a href="#ga9c564b4dd7d8fa4c6f4b32dd95fc33a"></a><br></td></tr>
50<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#gc24fadc1d42b65ca3563e40bc1f0fec1">dWorldQuickStep</a> (dWorldID w, dReal stepsize)</td></tr>
51
52<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Step the world.  <a href="#gc24fadc1d42b65ca3563e40bc1f0fec1"></a><br></td></tr>
53<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g9d852689d87d28a3d4947eda59c5ba7e">dWorldSetQuickStepNumIterations</a> (dWorldID, int num)</td></tr>
54
55<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Set the number of iterations that the QuickStep method performs per step.  <a href="#g9d852689d87d28a3d4947eda59c5ba7e"></a><br></td></tr>
56<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API int&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#ga51acfac06347fd27ff926d37672ce3c">dWorldGetQuickStepNumIterations</a> (dWorldID)</td></tr>
57
58<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get the number of iterations that the QuickStep method performs per step.  <a href="#ga51acfac06347fd27ff926d37672ce3c"></a><br></td></tr>
59<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#gf741ee61e3f9981ae102729f23aad535">dWorldSetQuickStepW</a> (dWorldID, dReal over_relaxation)</td></tr>
60
61<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Set the SOR over-relaxation parameter.  <a href="#gf741ee61e3f9981ae102729f23aad535"></a><br></td></tr>
62<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API dReal&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#ga7fef06f7a8293f21778939dfea36951">dWorldGetQuickStepW</a> (dWorldID)</td></tr>
63
64<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get the SOR over-relaxation parameter.  <a href="#ga7fef06f7a8293f21778939dfea36951"></a><br></td></tr>
65<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g2cec4be3f40d49c5950ceac1a28440d8">dWorldSetContactMaxCorrectingVel</a> (dWorldID, dReal vel)</td></tr>
66
67<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Set the maximum correcting velocity that contacts are allowed to generate.  <a href="#g2cec4be3f40d49c5950ceac1a28440d8"></a><br></td></tr>
68<tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="g7673e6d0db3ddb319642caea7d14959d"></a><!-- doxytag: member="world::dWorldGetContactMaxCorrectingVel" ref="g7673e6d0db3ddb319642caea7d14959d" args="(dWorldID)" -->
69ODE_API dReal&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g7673e6d0db3ddb319642caea7d14959d">dWorldGetContactMaxCorrectingVel</a> (dWorldID)</td></tr>
70
71<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get the maximum correcting velocity that contacts are allowed to generated. <br></td></tr>
72<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g8f6f964bc15b6cf0937d3214f6e3a1f1">dWorldSetContactSurfaceLayer</a> (dWorldID, dReal depth)</td></tr>
73
74<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Set the depth of the surface layer around all geometry objects.  <a href="#g8f6f964bc15b6cf0937d3214f6e3a1f1"></a><br></td></tr>
75<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API dReal&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#g97e1c98f55d9b56d00e7838900ad5e58">dWorldGetContactSurfaceLayer</a> (dWorldID)</td></tr>
76
77<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Get the depth of the surface layer around all geometry objects.  <a href="#g97e1c98f55d9b56d00e7838900ad5e58"></a><br></td></tr>
78<tr><td class="memItemLeft" nowrap align="right" valign="top">ODE_API void&nbsp;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__world.html#gefa68c714bb3c8f70503f101ea062c03">dWorldStepFast1</a> (dWorldID, dReal stepsize, int maxiterations)</td></tr>
79
80<tr><td class="mdescLeft">&nbsp;</td><td class="mdescRight">Step the world using the StepFast1 algorithm.  <a href="#gefa68c714bb3c8f70503f101ea062c03"></a><br></td></tr>
81</table>
82<hr><a name="_details"></a><h2>Detailed Description</h2>
83The world object is a container for rigid bodies and joints. Objects in different worlds can not interact, for example rigid bodies from two different worlds can not collide.<p>
84All the objects in a world exist at the same point in time, thus one reason to use separate worlds is to simulate systems at different rates. Most applications will only need one world. <hr><h2>Function Documentation</h2>
85<a class="anchor" name="g929067266d630fb745f752042d685fc7"></a><!-- doxytag: member="objects.h::dWorldCreate" ref="g929067266d630fb745f752042d685fc7" args="(void)" -->
86<div class="memitem">
87<div class="memproto">
88      <table class="memname">
89        <tr>
90          <td class="memname">ODE_API dWorldID dWorldCreate           </td>
91          <td>(</td>
92          <td class="paramtype">void&nbsp;</td>
93          <td class="paramname">          </td>
94          <td>&nbsp;)&nbsp;</td>
95          <td width="100%"></td>
96        </tr>
97      </table>
98</div>
99<div class="memdoc">
100
101<p>
102Create a new, empty world and return its ID number.
103<p>
104<dl class="return" compact><dt><b>Returns:</b></dt><dd>an identifier </dd></dl>
105
106</div>
107</div><p>
108<a class="anchor" name="g5a2e5b1d2d6a1376dca239b488e629f9"></a><!-- doxytag: member="objects.h::dWorldDestroy" ref="g5a2e5b1d2d6a1376dca239b488e629f9" args="(dWorldID world)" -->
109<div class="memitem">
110<div class="memproto">
111      <table class="memname">
112        <tr>
113          <td class="memname">ODE_API void dWorldDestroy           </td>
114          <td>(</td>
115          <td class="paramtype">dWorldID&nbsp;</td>
116          <td class="paramname"> <em>world</em>          </td>
117          <td>&nbsp;)&nbsp;</td>
118          <td width="100%"></td>
119        </tr>
120      </table>
121</div>
122<div class="memdoc">
123
124<p>
125Destroy a world and everything in it.
126<p>
127This includes all bodies, and all joints that are not part of a joint group. Joints that are part of a joint group will be deactivated, and can be destroyed by calling, for example, <a class="el" href="group__joints.html#g6e055bac8a0a3261bda3b6d07499c4ea" title="Empty a joint group.">dJointGroupEmpty()</a>.<p>
128<dl compact><dt><b>Parameters:</b></dt><dd>
129  <table border="0" cellspacing="2" cellpadding="0">
130    <tr><td valign="top"></td><td valign="top"><em>world</em>&nbsp;</td><td>the identifier for the world the be destroyed. </td></tr>
131  </table>
132</dl>
133
134</div>
135</div><p>
136<a class="anchor" name="gc7a431f2b3fc6f887fe91ad676828ba3"></a><!-- doxytag: member="objects.h::dWorldGetCFM" ref="gc7a431f2b3fc6f887fe91ad676828ba3" args="(dWorldID)" -->
137<div class="memitem">
138<div class="memproto">
139      <table class="memname">
140        <tr>
141          <td class="memname">ODE_API dReal dWorldGetCFM           </td>
142          <td>(</td>
143          <td class="paramtype">dWorldID&nbsp;</td>
144          <td class="paramname">          </td>
145          <td>&nbsp;)&nbsp;</td>
146          <td width="100%"></td>
147        </tr>
148      </table>
149</div>
150<div class="memdoc">
151
152<p>
153Get the constraint force mixing value.
154<p>
155<dl class="return" compact><dt><b>Returns:</b></dt><dd>CFM value </dd></dl>
156
157</div>
158</div><p>
159<a class="anchor" name="g97e1c98f55d9b56d00e7838900ad5e58"></a><!-- doxytag: member="objects.h::dWorldGetContactSurfaceLayer" ref="g97e1c98f55d9b56d00e7838900ad5e58" args="(dWorldID)" -->
160<div class="memitem">
161<div class="memproto">
162      <table class="memname">
163        <tr>
164          <td class="memname">ODE_API dReal dWorldGetContactSurfaceLayer           </td>
165          <td>(</td>
166          <td class="paramtype">dWorldID&nbsp;</td>
167          <td class="paramname">          </td>
168          <td>&nbsp;)&nbsp;</td>
169          <td width="100%"></td>
170        </tr>
171      </table>
172</div>
173<div class="memdoc">
174
175<p>
176Get the depth of the surface layer around all geometry objects.
177<p>
178<dl class="return" compact><dt><b>Returns:</b></dt><dd>the depth </dd></dl>
179
180</div>
181</div><p>
182<a class="anchor" name="g033cd87a0b22889a94d4d84149bda5a0"></a><!-- doxytag: member="objects.h::dWorldGetERP" ref="g033cd87a0b22889a94d4d84149bda5a0" args="(dWorldID)" -->
183<div class="memitem">
184<div class="memproto">
185      <table class="memname">
186        <tr>
187          <td class="memname">ODE_API dReal dWorldGetERP           </td>
188          <td>(</td>
189          <td class="paramtype">dWorldID&nbsp;</td>
190          <td class="paramname">          </td>
191          <td>&nbsp;)&nbsp;</td>
192          <td width="100%"></td>
193        </tr>
194      </table>
195</div>
196<div class="memdoc">
197
198<p>
199Get the error reduction parameter.
200<p>
201<dl class="return" compact><dt><b>Returns:</b></dt><dd>ERP value </dd></dl>
202
203</div>
204</div><p>
205<a class="anchor" name="ga51acfac06347fd27ff926d37672ce3c"></a><!-- doxytag: member="objects.h::dWorldGetQuickStepNumIterations" ref="ga51acfac06347fd27ff926d37672ce3c" args="(dWorldID)" -->
206<div class="memitem">
207<div class="memproto">
208      <table class="memname">
209        <tr>
210          <td class="memname">ODE_API int dWorldGetQuickStepNumIterations           </td>
211          <td>(</td>
212          <td class="paramtype">dWorldID&nbsp;</td>
213          <td class="paramname">          </td>
214          <td>&nbsp;)&nbsp;</td>
215          <td width="100%"></td>
216        </tr>
217      </table>
218</div>
219<div class="memdoc">
220
221<p>
222Get the number of iterations that the QuickStep method performs per step.
223<p>
224<dl class="return" compact><dt><b>Returns:</b></dt><dd>nr of iterations </dd></dl>
225
226</div>
227</div><p>
228<a class="anchor" name="ga7fef06f7a8293f21778939dfea36951"></a><!-- doxytag: member="objects.h::dWorldGetQuickStepW" ref="ga7fef06f7a8293f21778939dfea36951" args="(dWorldID)" -->
229<div class="memitem">
230<div class="memproto">
231      <table class="memname">
232        <tr>
233          <td class="memname">ODE_API dReal dWorldGetQuickStepW           </td>
234          <td>(</td>
235          <td class="paramtype">dWorldID&nbsp;</td>
236          <td class="paramname">          </td>
237          <td>&nbsp;)&nbsp;</td>
238          <td width="100%"></td>
239        </tr>
240      </table>
241</div>
242<div class="memdoc">
243
244<p>
245Get the SOR over-relaxation parameter.
246<p>
247<dl class="return" compact><dt><b>Returns:</b></dt><dd>the over-relaxation setting </dd></dl>
248
249</div>
250</div><p>
251<a class="anchor" name="ga9c564b4dd7d8fa4c6f4b32dd95fc33a"></a><!-- doxytag: member="objects.h::dWorldImpulseToForce" ref="ga9c564b4dd7d8fa4c6f4b32dd95fc33a" args="(dWorldID, dReal stepsize, dReal ix, dReal iy, dReal iz, dVector3 force)" -->
252<div class="memitem">
253<div class="memproto">
254      <table class="memname">
255        <tr>
256          <td class="memname">ODE_API void dWorldImpulseToForce           </td>
257          <td>(</td>
258          <td class="paramtype">dWorldID&nbsp;</td>
259          <td class="paramname">, </td>
260        </tr>
261        <tr>
262          <td class="paramkey"></td>
263          <td></td>
264          <td class="paramtype">dReal&nbsp;</td>
265          <td class="paramname"> <em>stepsize</em>, </td>
266        </tr>
267        <tr>
268          <td class="paramkey"></td>
269          <td></td>
270          <td class="paramtype">dReal&nbsp;</td>
271          <td class="paramname"> <em>ix</em>, </td>
272        </tr>
273        <tr>
274          <td class="paramkey"></td>
275          <td></td>
276          <td class="paramtype">dReal&nbsp;</td>
277          <td class="paramname"> <em>iy</em>, </td>
278        </tr>
279        <tr>
280          <td class="paramkey"></td>
281          <td></td>
282          <td class="paramtype">dReal&nbsp;</td>
283          <td class="paramname"> <em>iz</em>, </td>
284        </tr>
285        <tr>
286          <td class="paramkey"></td>
287          <td></td>
288          <td class="paramtype">dVector3&nbsp;</td>
289          <td class="paramname"> <em>force</em></td><td>&nbsp;</td>
290        </tr>
291        <tr>
292          <td></td>
293          <td>)</td>
294          <td></td><td></td><td width="100%"></td>
295        </tr>
296      </table>
297</div>
298<div class="memdoc">
299
300<p>
301Converts an impulse to a force.
302<p>
303<dl class="remark" compact><dt><b>Remarks:</b></dt><dd>If you want to apply a linear or angular impulse to a rigid body, instead of a force or a torque, then you can use this function to convert the desired impulse into a force/torque vector before calling the BodyAdd... function. The current algorithm simply scales the impulse by 1/stepsize, where stepsize is the step size for the next step that will be taken. This function is given a dWorldID because, in the future, the force computation may depend on integrator parameters that are set as properties of the world. </dd></dl>
304
305</div>
306</div><p>
307<a class="anchor" name="gc24fadc1d42b65ca3563e40bc1f0fec1"></a><!-- doxytag: member="objects.h::dWorldQuickStep" ref="gc24fadc1d42b65ca3563e40bc1f0fec1" args="(dWorldID w, dReal stepsize)" -->
308<div class="memitem">
309<div class="memproto">
310      <table class="memname">
311        <tr>
312          <td class="memname">ODE_API void dWorldQuickStep           </td>
313          <td>(</td>
314          <td class="paramtype">dWorldID&nbsp;</td>
315          <td class="paramname"> <em>w</em>, </td>
316        </tr>
317        <tr>
318          <td class="paramkey"></td>
319          <td></td>
320          <td class="paramtype">dReal&nbsp;</td>
321          <td class="paramname"> <em>stepsize</em></td><td>&nbsp;</td>
322        </tr>
323        <tr>
324          <td></td>
325          <td>)</td>
326          <td></td><td></td><td width="100%"></td>
327        </tr>
328      </table>
329</div>
330<div class="memdoc">
331
332<p>
333Step the world.
334<p>
335<dl class="remark" compact><dt><b>Remarks:</b></dt><dd>This uses an iterative method that takes time on the order of m*N and memory on the order of m, where m is the total number of constraint rows N is the number of iterations. For large systems this is a lot faster than <a class="el" href="group__world.html#g8f547ebeb3deed27e0f7b8143d475f50" title="Step the world.">dWorldStep()</a>, but it is less accurate. <p>
336QuickStep is great for stacks of objects especially when the auto-disable feature is used as well. However, it has poor accuracy for near-singular systems. Near-singular systems can occur when using high-friction contacts, motors, or certain articulated structures. For example, a robot with multiple legs sitting on the ground may be near-singular. <p>
337There are ways to help overcome QuickStep's inaccuracy problems: <ul>
338<li>Increase CFM. </li>
339<li>Reduce the number of contacts in your system (e.g. use the minimum number of contacts for the feet of a robot or creature). </li>
340<li>Don't use excessive friction in the contacts. </li>
341<li>Use contact slip if appropriate </li>
342<li>Avoid kinematic loops (however, kinematic loops are inevitable in legged creatures). </li>
343<li>Don't use excessive motor strength.  force-based motors instead of velocity-based motors.</li>
344</ul>
345Increasing the number of QuickStep iterations may help a little bit, but it is not going to help much if your system is really near singular. </dd></dl>
346
347</div>
348</div><p>
349<a class="anchor" name="g8b7913fe46d0afc468418c655da79233"></a><!-- doxytag: member="objects.h::dWorldSetCFM" ref="g8b7913fe46d0afc468418c655da79233" args="(dWorldID, dReal cfm)" -->
350<div class="memitem">
351<div class="memproto">
352      <table class="memname">
353        <tr>
354          <td class="memname">ODE_API void dWorldSetCFM           </td>
355          <td>(</td>
356          <td class="paramtype">dWorldID&nbsp;</td>
357          <td class="paramname">, </td>
358        </tr>
359        <tr>
360          <td class="paramkey"></td>
361          <td></td>
362          <td class="paramtype">dReal&nbsp;</td>
363          <td class="paramname"> <em>cfm</em></td><td>&nbsp;</td>
364        </tr>
365        <tr>
366          <td></td>
367          <td>)</td>
368          <td></td><td></td><td width="100%"></td>
369        </tr>
370      </table>
371</div>
372<div class="memdoc">
373
374<p>
375Set the global CFM (constraint force mixing) value.
376<p>
377<dl compact><dt><b>Parameters:</b></dt><dd>
378  <table border="0" cellspacing="2" cellpadding="0">
379    <tr><td valign="top"></td><td valign="top"><em>cfm</em>&nbsp;</td><td>Typical values are in the range {10^{-9}} -- 1. The default is 10^-5 if single precision is being used, or 10^-10 if double precision is being used. </td></tr>
380  </table>
381</dl>
382
383</div>
384</div><p>
385<a class="anchor" name="g2cec4be3f40d49c5950ceac1a28440d8"></a><!-- doxytag: member="objects.h::dWorldSetContactMaxCorrectingVel" ref="g2cec4be3f40d49c5950ceac1a28440d8" args="(dWorldID, dReal vel)" -->
386<div class="memitem">
387<div class="memproto">
388      <table class="memname">
389        <tr>
390          <td class="memname">ODE_API void dWorldSetContactMaxCorrectingVel           </td>
391          <td>(</td>
392          <td class="paramtype">dWorldID&nbsp;</td>
393          <td class="paramname">, </td>
394        </tr>
395        <tr>
396          <td class="paramkey"></td>
397          <td></td>
398          <td class="paramtype">dReal&nbsp;</td>
399          <td class="paramname"> <em>vel</em></td><td>&nbsp;</td>
400        </tr>
401        <tr>
402          <td></td>
403          <td>)</td>
404          <td></td><td></td><td width="100%"></td>
405        </tr>
406      </table>
407</div>
408<div class="memdoc">
409
410<p>
411Set the maximum correcting velocity that contacts are allowed to generate.
412<p>
413<dl compact><dt><b>Parameters:</b></dt><dd>
414  <table border="0" cellspacing="2" cellpadding="0">
415    <tr><td valign="top"></td><td valign="top"><em>vel</em>&nbsp;</td><td>The default value is infinity (i.e. no limit). </td></tr>
416  </table>
417</dl>
418<dl class="remark" compact><dt><b>Remarks:</b></dt><dd>Reducing this value can help prevent "popping" of deeply embedded objects. </dd></dl>
419
420</div>
421</div><p>
422<a class="anchor" name="g8f6f964bc15b6cf0937d3214f6e3a1f1"></a><!-- doxytag: member="objects.h::dWorldSetContactSurfaceLayer" ref="g8f6f964bc15b6cf0937d3214f6e3a1f1" args="(dWorldID, dReal depth)" -->
423<div class="memitem">
424<div class="memproto">
425      <table class="memname">
426        <tr>
427          <td class="memname">ODE_API void dWorldSetContactSurfaceLayer           </td>
428          <td>(</td>
429          <td class="paramtype">dWorldID&nbsp;</td>
430          <td class="paramname">, </td>
431        </tr>
432        <tr>
433          <td class="paramkey"></td>
434          <td></td>
435          <td class="paramtype">dReal&nbsp;</td>
436          <td class="paramname"> <em>depth</em></td><td>&nbsp;</td>
437        </tr>
438        <tr>
439          <td></td>
440          <td>)</td>
441          <td></td><td></td><td width="100%"></td>
442        </tr>
443      </table>
444</div>
445<div class="memdoc">
446
447<p>
448Set the depth of the surface layer around all geometry objects.
449<p>
450<dl class="remark" compact><dt><b>Remarks:</b></dt><dd>Contacts are allowed to sink into the surface layer up to the given depth before coming to rest. </dd></dl>
451<dl compact><dt><b>Parameters:</b></dt><dd>
452  <table border="0" cellspacing="2" cellpadding="0">
453    <tr><td valign="top"></td><td valign="top"><em>depth</em>&nbsp;</td><td>The default value is zero. </td></tr>
454  </table>
455</dl>
456<dl class="remark" compact><dt><b>Remarks:</b></dt><dd>Increasing this to some small value (e.g. 0.001) can help prevent jittering problems due to contacts being repeatedly made and broken. </dd></dl>
457
458</div>
459</div><p>
460<a class="anchor" name="gacd0778bdaa939d22f093fc2d5d5f868"></a><!-- doxytag: member="objects.h::dWorldSetERP" ref="gacd0778bdaa939d22f093fc2d5d5f868" args="(dWorldID, dReal erp)" -->
461<div class="memitem">
462<div class="memproto">
463      <table class="memname">
464        <tr>
465          <td class="memname">ODE_API void dWorldSetERP           </td>
466          <td>(</td>
467          <td class="paramtype">dWorldID&nbsp;</td>
468          <td class="paramname">, </td>
469        </tr>
470        <tr>
471          <td class="paramkey"></td>
472          <td></td>
473          <td class="paramtype">dReal&nbsp;</td>
474          <td class="paramname"> <em>erp</em></td><td>&nbsp;</td>
475        </tr>
476        <tr>
477          <td></td>
478          <td>)</td>
479          <td></td><td></td><td width="100%"></td>
480        </tr>
481      </table>
482</div>
483<div class="memdoc">
484
485<p>
486Set the global ERP value, that controls how much error correction is performed in each time step.
487<p>
488<dl compact><dt><b>Parameters:</b></dt><dd>
489  <table border="0" cellspacing="2" cellpadding="0">
490    <tr><td valign="top"></td><td valign="top"><em>dWorldID</em>&nbsp;</td><td>the identifier of the world. </td></tr>
491    <tr><td valign="top"></td><td valign="top"><em>erp</em>&nbsp;</td><td>Typical values are in the range 0.1--0.8. The default is 0.2. </td></tr>
492  </table>
493</dl>
494
495</div>
496</div><p>
497<a class="anchor" name="ga1b220b922215b335572c699cf8f8cad"></a><!-- doxytag: member="objects.h::dWorldSetGravity" ref="ga1b220b922215b335572c699cf8f8cad" args="(dWorldID, dReal x, dReal y, dReal z)" -->
498<div class="memitem">
499<div class="memproto">
500      <table class="memname">
501        <tr>
502          <td class="memname">ODE_API void dWorldSetGravity           </td>
503          <td>(</td>
504          <td class="paramtype">dWorldID&nbsp;</td>
505          <td class="paramname">, </td>
506        </tr>
507        <tr>
508          <td class="paramkey"></td>
509          <td></td>
510          <td class="paramtype">dReal&nbsp;</td>
511          <td class="paramname"> <em>x</em>, </td>
512        </tr>
513        <tr>
514          <td class="paramkey"></td>
515          <td></td>
516          <td class="paramtype">dReal&nbsp;</td>
517          <td class="paramname"> <em>y</em>, </td>
518        </tr>
519        <tr>
520          <td class="paramkey"></td>
521          <td></td>
522          <td class="paramtype">dReal&nbsp;</td>
523          <td class="paramname"> <em>z</em></td><td>&nbsp;</td>
524        </tr>
525        <tr>
526          <td></td>
527          <td>)</td>
528          <td></td><td></td><td width="100%"></td>
529        </tr>
530      </table>
531</div>
532<div class="memdoc">
533
534<p>
535Set the world's global gravity vector.
536<p>
537The units are m/s^2, so Earth's gravity vector would be (0,0,-9.81), assuming that +z is up. The default is no gravity, i.e. (0,0,0).
538</div>
539</div><p>
540<a class="anchor" name="g9d852689d87d28a3d4947eda59c5ba7e"></a><!-- doxytag: member="objects.h::dWorldSetQuickStepNumIterations" ref="g9d852689d87d28a3d4947eda59c5ba7e" args="(dWorldID, int num)" -->
541<div class="memitem">
542<div class="memproto">
543      <table class="memname">
544        <tr>
545          <td class="memname">ODE_API void dWorldSetQuickStepNumIterations           </td>
546          <td>(</td>
547          <td class="paramtype">dWorldID&nbsp;</td>
548          <td class="paramname">, </td>
549        </tr>
550        <tr>
551          <td class="paramkey"></td>
552          <td></td>
553          <td class="paramtype">int&nbsp;</td>
554          <td class="paramname"> <em>num</em></td><td>&nbsp;</td>
555        </tr>
556        <tr>
557          <td></td>
558          <td>)</td>
559          <td></td><td></td><td width="100%"></td>
560        </tr>
561      </table>
562</div>
563<div class="memdoc">
564
565<p>
566Set the number of iterations that the QuickStep method performs per step.
567<p>
568<dl class="remark" compact><dt><b>Remarks:</b></dt><dd>More iterations will give a more accurate solution, but will take longer to compute. </dd></dl>
569<dl compact><dt><b>Parameters:</b></dt><dd>
570  <table border="0" cellspacing="2" cellpadding="0">
571    <tr><td valign="top"></td><td valign="top"><em>num</em>&nbsp;</td><td>The default is 20 iterations. </td></tr>
572  </table>
573</dl>
574
575</div>
576</div><p>
577<a class="anchor" name="gf741ee61e3f9981ae102729f23aad535"></a><!-- doxytag: member="objects.h::dWorldSetQuickStepW" ref="gf741ee61e3f9981ae102729f23aad535" args="(dWorldID, dReal over_relaxation)" -->
578<div class="memitem">
579<div class="memproto">
580      <table class="memname">
581        <tr>
582          <td class="memname">ODE_API void dWorldSetQuickStepW           </td>
583          <td>(</td>
584          <td class="paramtype">dWorldID&nbsp;</td>
585          <td class="paramname">, </td>
586        </tr>
587        <tr>
588          <td class="paramkey"></td>
589          <td></td>
590          <td class="paramtype">dReal&nbsp;</td>
591          <td class="paramname"> <em>over_relaxation</em></td><td>&nbsp;</td>
592        </tr>
593        <tr>
594          <td></td>
595          <td>)</td>
596          <td></td><td></td><td width="100%"></td>
597        </tr>
598      </table>
599</div>
600<div class="memdoc">
601
602<p>
603Set the SOR over-relaxation parameter.
604<p>
605<dl compact><dt><b>Parameters:</b></dt><dd>
606  <table border="0" cellspacing="2" cellpadding="0">
607    <tr><td valign="top"></td><td valign="top"><em>over_relaxation</em>&nbsp;</td><td>value to use by SOR </td></tr>
608  </table>
609</dl>
610
611</div>
612</div><p>
613<a class="anchor" name="g8f547ebeb3deed27e0f7b8143d475f50"></a><!-- doxytag: member="objects.h::dWorldStep" ref="g8f547ebeb3deed27e0f7b8143d475f50" args="(dWorldID, dReal stepsize)" -->
614<div class="memitem">
615<div class="memproto">
616      <table class="memname">
617        <tr>
618          <td class="memname">ODE_API void dWorldStep           </td>
619          <td>(</td>
620          <td class="paramtype">dWorldID&nbsp;</td>
621          <td class="paramname">, </td>
622        </tr>
623        <tr>
624          <td class="paramkey"></td>
625          <td></td>
626          <td class="paramtype">dReal&nbsp;</td>
627          <td class="paramname"> <em>stepsize</em></td><td>&nbsp;</td>
628        </tr>
629        <tr>
630          <td></td>
631          <td>)</td>
632          <td></td><td></td><td width="100%"></td>
633        </tr>
634      </table>
635</div>
636<div class="memdoc">
637
638<p>
639Step the world.
640<p>
641This uses a "big matrix" method that takes time on the order of m^3 and memory on the order of m^2, where m is the total number of constraint rows. For large systems this will use a lot of memory and can be very slow, but this is currently the most accurate method.<p>
642<dl compact><dt><b>Parameters:</b></dt><dd>
643  <table border="0" cellspacing="2" cellpadding="0">
644    <tr><td valign="top"></td><td valign="top"><em>stepsize</em>&nbsp;</td><td>The number of seconds that the simulation has to advance. </td></tr>
645  </table>
646</dl>
647
648</div>
649</div><p>
650<a class="anchor" name="gefa68c714bb3c8f70503f101ea062c03"></a><!-- doxytag: member="objects.h::dWorldStepFast1" ref="gefa68c714bb3c8f70503f101ea062c03" args="(dWorldID, dReal stepsize, int maxiterations)" -->
651<div class="memitem">
652<div class="memproto">
653      <table class="memname">
654        <tr>
655          <td class="memname">ODE_API void dWorldStepFast1           </td>
656          <td>(</td>
657          <td class="paramtype">dWorldID&nbsp;</td>
658          <td class="paramname">, </td>
659        </tr>
660        <tr>
661          <td class="paramkey"></td>
662          <td></td>
663          <td class="paramtype">dReal&nbsp;</td>
664          <td class="paramname"> <em>stepsize</em>, </td>
665        </tr>
666        <tr>
667          <td class="paramkey"></td>
668          <td></td>
669          <td class="paramtype">int&nbsp;</td>
670          <td class="paramname"> <em>maxiterations</em></td><td>&nbsp;</td>
671        </tr>
672        <tr>
673          <td></td>
674          <td>)</td>
675          <td></td><td></td><td width="100%"></td>
676        </tr>
677      </table>
678</div>
679<div class="memdoc">
680
681<p>
682Step the world using the StepFast1 algorithm.
683<p>
684<dl compact><dt><b>Parameters:</b></dt><dd>
685  <table border="0" cellspacing="2" cellpadding="0">
686    <tr><td valign="top"></td><td valign="top"><em>stepsize</em>&nbsp;</td><td>the nr of seconds to advance the simulation. </td></tr>
687    <tr><td valign="top"></td><td valign="top"><em>maxiterations</em>&nbsp;</td><td>The number of iterations to perform. </td></tr>
688  </table>
689</dl>
690
691</div>
692</div><p>
693<hr size="1"><address style="text-align: right;"><small>Generated on Fri Oct 12 08:36:51 2007 for Open Dynamics Engine by&nbsp;
694<a href="http://www.doxygen.org/index.html">
695<img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.5.3 </small></address>
696</body>
697</html>
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