[ODE] Simulating a Cylinder.
Gary R. Van Sickle
g.r.vansickle at worldnet.att.net
Thu Aug 22 23:32:01 2002
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MessageThere's no flat-endcap cylinder collision support in ODE currently.
You might try a bounding box instead; still not right, but if you need the
flat ends more than the round sides it might do what you need.
I'm not sure what to tell you about your stability problems. The increased
mass helping makes some sense if perhaps you were getting huge contact
impulses or something.
--
Gary R. Van Sickle
Brewer. Patriot.
-----Original Message-----
From: ode-admin@q12.org [mailto:ode-admin@q12.org]On Behalf Of Keshav
Sent: Friday, August 23, 2002 1:16 AM
To: ode@q12.org
Subject: [ODE] Simulating a Cylinder.
Hello,
I was trying to simulate a cylinder using ODE.
I'm using the standard ODE capped cylinder geometry object.
And, I'm using a "plane" object as my ground or floor.
I drop off the cylinder from a small height.
Everythings fine, until the cylinder touches the floor plane.
As soon as it touches the floor, it vanishes.
When I check it's position, it shows as NAN (not a number).
When I add global ERP, say 0.5, then, the cylinder stays for about 2
seconds after hitting the ground, and then, it disappears.
My cylinder's physical parameters are:
Radius: 1.13
Length: 0.6
Mass: 10
I kept radius and length the same, and increased the mass to 1000.
Now, surprisingly, the simulation was very stable.
But, I noticed this -> since my cylinder's radius is much larger than it's
length, the cylinder should actually be resting on the
flat side, i.e on the caps, isn't it?
Later, when I went through the documentation again, it says that, there
are two half-spheres as caps for the cylinder.
Is there anyway of creating a cylinder with flat caps, instead of half
sphere caps?
How can I simulate a cylinder (with flat caps at both ends) using ODE
successfully?
Has anybody simulated a cylinder (with flat caps at both ends) using ODE?
- Keshav.
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<DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
class=3D460302606-23082002>There's no flat-endcap cylinder collision =
support in=20
ODE currently. You might try a bounding box instead; still not =
right, but=20
if you need the flat ends more than the round sides it might do what you =
need.</SPAN></FONT></DIV>
<DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
class=3D460302606-23082002></SPAN></FONT> </DIV>
<DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN =
class=3D460302606-23082002>I'm=20
not sure what to tell you about your stability problems. The =
increased=20
mass helping makes some sense if perhaps you were getting huge contact =
impulses=20
or something.</SPAN></FONT></DIV>
<DIV> </DIV>
<P><FONT size=3D2>--<BR>Gary R. Van Sickle<BR>Brewer. Patriot. =
</FONT></P>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px =
solid; MARGIN-RIGHT: 0px">
<DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT =
face=3DTahoma=20
size=3D2>-----Original Message-----<BR><B>From:</B> ode-admin@q12.org=20
[mailto:ode-admin@q12.org]<B>On Behalf Of </B>Keshav<BR><B>Sent:</B> =
Friday,=20
August 23, 2002 1:16 AM<BR><B>To:</B> ode@q12.org<BR><B>Subject:</B> =
[ODE]=20
Simulating a Cylinder.<BR><BR></FONT></DIV>
<DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial=20
size=3D2>Hello,</FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>I was trying to simulate a cylinder =
using=20
ODE.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>I'm using the standard ODE capped =
cylinder=20
geometry object.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>And, I'm using a "plane" object as my =
ground or=20
floor.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>I drop off the cylinder from a small=20
height.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>Everythings fine, until the cylinder =
touches the=20
floor plane.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>As soon as it touches the floor, it=20
vanishes.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>When I check it's position, it shows as NAN =
(not a=20
number).</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>When I add global ERP, say 0.5, then, the =
cylinder=20
stays for about 2 seconds after hitting the ground, and then, it=20
disappears.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>My cylinder's physical parameters=20
are:</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002> Radius:=20
1.13</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002> Length: =20
0.6</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002> Mass: =20
10</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>I kept radius and length the same, and =
increased the=20
mass to 1000.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>Now, surprisingly, the simulation was very=20
stable.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>But, I noticed this -> since my =
cylinder's radius=20
is much larger than it's length, the cylinder should actually be =
resting on=20
the </SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>flat side, i.e on the caps, isn't =
it?</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>Later, when I went through the =
documentation again,=20
it says that, there are two half-spheres as caps for the=20
cylinder.</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>Is there anyway of creating a cylinder =
with flat=20
caps, instead of half sphere caps?</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>How can I simulate a cylinder (with flat =
caps at both=20
ends) using ODE successfully?</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002>Has anybody simulated a cylinder (with flat =
caps at=20
both ends) using ODE?</SPAN></FONT></SPAN></DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial =
size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN><SPAN=20
class=3D960482107-13082002><FONT face=3DArial size=3D2><SPAN=20
class=3D111145714-14082002></SPAN></FONT></SPAN> </DIV>
<DIV><SPAN class=3D960482107-13082002><FONT face=3DArial size=3D2>-=20
Keshav.</FONT></SPAN></DIV></DIV></BLOCKQUOTE></BODY></HTML>
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