## Re: [Playerstage-users] Limb interface

 Re: [Playerstage-users] Limb interface From: Konrad Banachowicz - 2009-06-22 17:02:21 Attachments: Message as HTML ```ok, but this way i can use position3d to control end-effector position instead of limb. So why we need limb interface, i think there should be single interface to control end effector. Limb should provide full control over end effector. Maybe position3d should be used instead ? 2009/6/22 Geoff > If you want to control the linear and angular velocity of the end > effector, you should make your driver provide a position3d interface as > well. > > Geoff > > Konrad Banachowicz wrote: > > Thanks for explanation. > > I have few more questions. > > I want to be able to get and set linear and angular velocity of the end > > effector. > > As far as i know this will require modification of interface. > > How to describe velocities in the same manner like orientation ? > > How to add it to interface ? > > Velocities should be part of limb_data or be available on request ? > > > > 2009/6/21 Geoff > > > > > The limb interface uses the standard method of specifying orientation > of > > an end effector. The two vectors used are the approach vector and the > > orientation vector. The approach vector is a vector that runs down > the > > length of the end effector in its direction of approach, i.e. it > points > > where the end effector is pointing. The orientation vector is > > perpendicular to the approach vector, usually in the same horizontal > > plane in end effector space. It is used to define the end effector's > > rotation around the axis that is parallel to the approach vector. > > Usually, a third vector is given as well. This is the normal vector. > It > > is perpendicular to both the approach and orientation vectors. > However, > > because it can be calculated using the cross product of the other two > > vectors, there is no need to transmit it. All vectors extend from the > > origin of the end effector, that is, the final joint before it. > > Together, they also define the three axes of the end effector > coordinate > > space. > > > > As an example, think of your hand. If your hand is straight, then > there > > is a straight line running down your lower arm and through your hand. > > The approach vector extends from your wrist out through your hand > along > > this line. Hold your thumb out at a right angle to your hand, keeping > it > > flat in the same plane as your fingers. The orientation vector runs > from > > your wrist out either in the same direction as your thumb or in the > > opposite direction, depending on which hand you're looking at and > > whether you're using a right- or left-handed coordinate system, and > > perpendicular to the line down your arm. The normal vector will run > from > > your wrist perpendicular to both of the other two. Typically it will > be > > defined to point "up." > > > > Now try rotating your hand around your wrist along the line that runs > > down your arm. The orientation and normal vectors will move, while > the > > approach vector stays the same. If you point your hand downwards, the > > orientation vector stays the same while the normal and approach > vectors > > move. > > > > If you want to make a rotation matrix from these three vectors, you > can > > do it by using dot products to calculate their angles around some > other > > coordinate space's axes. > > > > Geoff > > > > Konrad Banachowicz wrote: > > > Hi all, > > > I'm writing IK driver for manipulator and I have few questions > about > > > limb interface. > > > Why orientation is discribed with two vectors instead of > > player_pose3d_t ? > > > How exactly these vectors describe orientation, how to create > rotation > > > matrix from them? > > > > > > > > > ------------------------------------------------------------------------------ > > Are you an open source citizen? Join us for the Open Source Bridge > > conference! > > Portland, OR, June 17-19. Two days of sessions, one day of > > unconference: \$250. > > Need another reason to go? 24-hour hacker lounge. Register today! > > > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > > _______________________________________________ > > Playerstage-users mailing list > > Playerstage-users@... > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-users > > > > > > > > ------------------------------------------------------------------------ > > > > > ------------------------------------------------------------------------------ > > Are you an open source citizen? Join us for the Open Source Bridge > conference! > > Portland, OR, June 17-19. Two days of sessions, one day of unconference: > \$250. > > Need another reason to go? 24-hour hacker lounge. Register today! > > > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Playerstage-users mailing list > > Playerstage-users@... > > https://lists.sourceforge.net/lists/listinfo/playerstage-users > > > ------------------------------------------------------------------------------ > Are you an open source citizen? Join us for the Open Source Bridge > conference! > Portland, OR, June 17-19. Two days of sessions, one day of unconference: > \$250. > Need another reason to go? 24-hour hacker lounge. Register today! > > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > _______________________________________________ > Playerstage-users mailing list > Playerstage-users@... > https://lists.sourceforge.net/lists/listinfo/playerstage-users > ```

 [Playerstage-users] Limb interface From: Konrad Banachowicz - 2009-06-20 20:21:03 Attachments: Message as HTML ```Hi all, I'm writing IK driver for manipulator and I have few questions about limb interface. Why orientation is discribed with two vectors instead of player_pose3d_t ? How exactly these vectors describe orientation, how to create rotation matrix from them? ```
 Re: [Playerstage-users] Limb interface From: Geoff - 2009-06-21 15:56:09 ```The limb interface uses the standard method of specifying orientation of an end effector. The two vectors used are the approach vector and the orientation vector. The approach vector is a vector that runs down the length of the end effector in its direction of approach, i.e. it points where the end effector is pointing. The orientation vector is perpendicular to the approach vector, usually in the same horizontal plane in end effector space. It is used to define the end effector's rotation around the axis that is parallel to the approach vector. Usually, a third vector is given as well. This is the normal vector. It is perpendicular to both the approach and orientation vectors. However, because it can be calculated using the cross product of the other two vectors, there is no need to transmit it. All vectors extend from the origin of the end effector, that is, the final joint before it. Together, they also define the three axes of the end effector coordinate space. As an example, think of your hand. If your hand is straight, then there is a straight line running down your lower arm and through your hand. The approach vector extends from your wrist out through your hand along this line. Hold your thumb out at a right angle to your hand, keeping it flat in the same plane as your fingers. The orientation vector runs from your wrist out either in the same direction as your thumb or in the opposite direction, depending on which hand you're looking at and whether you're using a right- or left-handed coordinate system, and perpendicular to the line down your arm. The normal vector will run from your wrist perpendicular to both of the other two. Typically it will be defined to point "up." Now try rotating your hand around your wrist along the line that runs down your arm. The orientation and normal vectors will move, while the approach vector stays the same. If you point your hand downwards, the orientation vector stays the same while the normal and approach vectors move. If you want to make a rotation matrix from these three vectors, you can do it by using dot products to calculate their angles around some other coordinate space's axes. Geoff Konrad Banachowicz wrote: > Hi all, > I'm writing IK driver for manipulator and I have few questions about > limb interface. > Why orientation is discribed with two vectors instead of player_pose3d_t ? > How exactly these vectors describe orientation, how to create rotation > matrix from them? ```
 Re: [Playerstage-users] Limb interface From: Konrad Banachowicz - 2009-06-21 16:40:27 Attachments: Message as HTML ```Thanks for explanation. I have few more questions. I want to be able to get and set linear and angular velocity of the end effector. As far as i know this will require modification of interface. How to describe velocities in the same manner like orientation ? How to add it to interface ? Velocities should be part of limb_data or be available on request ? 2009/6/21 Geoff > The limb interface uses the standard method of specifying orientation of > an end effector. The two vectors used are the approach vector and the > orientation vector. The approach vector is a vector that runs down the > length of the end effector in its direction of approach, i.e. it points > where the end effector is pointing. The orientation vector is > perpendicular to the approach vector, usually in the same horizontal > plane in end effector space. It is used to define the end effector's > rotation around the axis that is parallel to the approach vector. > Usually, a third vector is given as well. This is the normal vector. It > is perpendicular to both the approach and orientation vectors. However, > because it can be calculated using the cross product of the other two > vectors, there is no need to transmit it. All vectors extend from the > origin of the end effector, that is, the final joint before it. > Together, they also define the three axes of the end effector coordinate > space. > > As an example, think of your hand. If your hand is straight, then there > is a straight line running down your lower arm and through your hand. > The approach vector extends from your wrist out through your hand along > this line. Hold your thumb out at a right angle to your hand, keeping it > flat in the same plane as your fingers. The orientation vector runs from > your wrist out either in the same direction as your thumb or in the > opposite direction, depending on which hand you're looking at and > whether you're using a right- or left-handed coordinate system, and > perpendicular to the line down your arm. The normal vector will run from > your wrist perpendicular to both of the other two. Typically it will be > defined to point "up." > > Now try rotating your hand around your wrist along the line that runs > down your arm. The orientation and normal vectors will move, while the > approach vector stays the same. If you point your hand downwards, the > orientation vector stays the same while the normal and approach vectors > move. > > If you want to make a rotation matrix from these three vectors, you can > do it by using dot products to calculate their angles around some other > coordinate space's axes. > > Geoff > > Konrad Banachowicz wrote: > > Hi all, > > I'm writing IK driver for manipulator and I have few questions about > > limb interface. > > Why orientation is discribed with two vectors instead of player_pose3d_t > ? > > How exactly these vectors describe orientation, how to create rotation > > matrix from them? > > > > > ------------------------------------------------------------------------------ > Are you an open source citizen? Join us for the Open Source Bridge > conference! > Portland, OR, June 17-19. Two days of sessions, one day of unconference: > \$250. > Need another reason to go? 24-hour hacker lounge. Register today! > > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > _______________________________________________ > Playerstage-users mailing list > Playerstage-users@... > https://lists.sourceforge.net/lists/listinfo/playerstage-users > ```
 Re: [Playerstage-users] Limb interface From: Toby Collett - 2009-06-21 18:25:24 Attachments: Message as HTML ```for fine control of the joints in a limb you could use the actarray interface to control the speed contraints etc and the limb interface for setting the goal pose... Toby 2009/6/21 Konrad Banachowicz > Thanks for explanation. > I have few more questions. > I want to be able to get and set linear and angular velocity of the end > effector. > As far as i know this will require modification of interface. > How to describe velocities in the same manner like orientation ? > How to add it to interface ? > Velocities should be part of limb_data or be available on request ? > > 2009/6/21 Geoff > > The limb interface uses the standard method of specifying orientation of >> an end effector. The two vectors used are the approach vector and the >> orientation vector. The approach vector is a vector that runs down the >> length of the end effector in its direction of approach, i.e. it points >> where the end effector is pointing. The orientation vector is >> perpendicular to the approach vector, usually in the same horizontal >> plane in end effector space. It is used to define the end effector's >> rotation around the axis that is parallel to the approach vector. >> Usually, a third vector is given as well. This is the normal vector. It >> is perpendicular to both the approach and orientation vectors. However, >> because it can be calculated using the cross product of the other two >> vectors, there is no need to transmit it. All vectors extend from the >> origin of the end effector, that is, the final joint before it. >> Together, they also define the three axes of the end effector coordinate >> space. >> >> As an example, think of your hand. If your hand is straight, then there >> is a straight line running down your lower arm and through your hand. >> The approach vector extends from your wrist out through your hand along >> this line. Hold your thumb out at a right angle to your hand, keeping it >> flat in the same plane as your fingers. The orientation vector runs from >> your wrist out either in the same direction as your thumb or in the >> opposite direction, depending on which hand you're looking at and >> whether you're using a right- or left-handed coordinate system, and >> perpendicular to the line down your arm. The normal vector will run from >> your wrist perpendicular to both of the other two. Typically it will be >> defined to point "up." >> >> Now try rotating your hand around your wrist along the line that runs >> down your arm. The orientation and normal vectors will move, while the >> approach vector stays the same. If you point your hand downwards, the >> orientation vector stays the same while the normal and approach vectors >> move. >> >> If you want to make a rotation matrix from these three vectors, you can >> do it by using dot products to calculate their angles around some other >> coordinate space's axes. >> >> Geoff >> >> Konrad Banachowicz wrote: >> > Hi all, >> > I'm writing IK driver for manipulator and I have few questions about >> > limb interface. >> > Why orientation is discribed with two vectors instead of player_pose3d_t >> ? >> > How exactly these vectors describe orientation, how to create rotation >> > matrix from them? >> >> >> >> >> ------------------------------------------------------------------------------ >> Are you an open source citizen? Join us for the Open Source Bridge >> conference! >> Portland, OR, June 17-19. Two days of sessions, one day of unconference: >> \$250. >> Need another reason to go? 24-hour hacker lounge. Register today! >> >> http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org >> _______________________________________________ >> Playerstage-users mailing list >> Playerstage-users@... >> https://lists.sourceforge.net/lists/listinfo/playerstage-users >> > > > > ------------------------------------------------------------------------------ > Are you an open source citizen? Join us for the Open Source Bridge > conference! > Portland, OR, June 17-19. Two days of sessions, one day of unconference: > \$250. > Need another reason to go? 24-hour hacker lounge. Register today! > > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > _______________________________________________ > Playerstage-users mailing list > Playerstage-users@... > https://lists.sourceforge.net/lists/listinfo/playerstage-users > > -- This email is intended for the addressee only and may contain privileged and/or confidential information ```
 Re: [Playerstage-users] Limb interface From: Konrad Banachowicz - 2009-06-21 19:04:53 Attachments: Message as HTML ```It not solve may problem. I want to set end effector velocity (visual sorvoing) and I don't know the goal pose. 2009/6/21 Toby Collett > > for fine control of the joints in a limb you could use the actarray > interface to control the speed contraints etc and the limb interface for > setting the goal pose... > > Toby > > 2009/6/21 Konrad Banachowicz > > Thanks for explanation. >> I have few more questions. >> I want to be able to get and set linear and angular velocity of the end >> effector. >> As far as i know this will require modification of interface. >> How to describe velocities in the same manner like orientation ? >> How to add it to interface ? >> Velocities should be part of limb_data or be available on request ? >> >> 2009/6/21 Geoff >> >> The limb interface uses the standard method of specifying orientation of >>> an end effector. The two vectors used are the approach vector and the >>> orientation vector. The approach vector is a vector that runs down the >>> length of the end effector in its direction of approach, i.e. it points >>> where the end effector is pointing. The orientation vector is >>> perpendicular to the approach vector, usually in the same horizontal >>> plane in end effector space. It is used to define the end effector's >>> rotation around the axis that is parallel to the approach vector. >>> Usually, a third vector is given as well. This is the normal vector. It >>> is perpendicular to both the approach and orientation vectors. However, >>> because it can be calculated using the cross product of the other two >>> vectors, there is no need to transmit it. All vectors extend from the >>> origin of the end effector, that is, the final joint before it. >>> Together, they also define the three axes of the end effector coordinate >>> space. >>> >>> As an example, think of your hand. If your hand is straight, then there >>> is a straight line running down your lower arm and through your hand. >>> The approach vector extends from your wrist out through your hand along >>> this line. Hold your thumb out at a right angle to your hand, keeping it >>> flat in the same plane as your fingers. The orientation vector runs from >>> your wrist out either in the same direction as your thumb or in the >>> opposite direction, depending on which hand you're looking at and >>> whether you're using a right- or left-handed coordinate system, and >>> perpendicular to the line down your arm. The normal vector will run from >>> your wrist perpendicular to both of the other two. Typically it will be >>> defined to point "up." >>> >>> Now try rotating your hand around your wrist along the line that runs >>> down your arm. The orientation and normal vectors will move, while the >>> approach vector stays the same. If you point your hand downwards, the >>> orientation vector stays the same while the normal and approach vectors >>> move. >>> >>> If you want to make a rotation matrix from these three vectors, you can >>> do it by using dot products to calculate their angles around some other >>> coordinate space's axes. >>> >>> Geoff >>> >>> Konrad Banachowicz wrote: >>> > Hi all, >>> > I'm writing IK driver for manipulator and I have few questions about >>> > limb interface. >>> > Why orientation is discribed with two vectors instead of >>> player_pose3d_t ? >>> > How exactly these vectors describe orientation, how to create rotation >>> > matrix from them? >>> >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> Are you an open source citizen? Join us for the Open Source Bridge >>> conference! >>> Portland, OR, June 17-19. Two days of sessions, one day of unconference: >>> \$250. >>> Need another reason to go? 24-hour hacker lounge. Register today! >>> >>> http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org >>> _______________________________________________ >>> Playerstage-users mailing list >>> Playerstage-users@... >>> https://lists.sourceforge.net/lists/listinfo/playerstage-users >>> >> >> >> >> ------------------------------------------------------------------------------ >> Are you an open source citizen? Join us for the Open Source Bridge >> conference! >> Portland, OR, June 17-19. Two days of sessions, one day of unconference: >> \$250. >> Need another reason to go? 24-hour hacker lounge. Register today! >> >> http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org >> _______________________________________________ >> Playerstage-users mailing list >> Playerstage-users@... >> https://lists.sourceforge.net/lists/listinfo/playerstage-users >> >> > > > -- > This email is intended for the addressee only and may contain privileged > and/or confidential information > > > ------------------------------------------------------------------------------ > Are you an open source citizen? Join us for the Open Source Bridge > conference! > Portland, OR, June 17-19. Two days of sessions, one day of unconference: > \$250. > Need another reason to go? 24-hour hacker lounge. Register today! > > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > _______________________________________________ > Playerstage-users mailing list > Playerstage-users@... > https://lists.sourceforge.net/lists/listinfo/playerstage-users > > ```
 Re: [Playerstage-users] Limb interface From: Geoff - 2009-06-22 15:22:41 ```If you want to control the linear and angular velocity of the end effector, you should make your driver provide a position3d interface as well. Geoff Konrad Banachowicz wrote: > Thanks for explanation. > I have few more questions. > I want to be able to get and set linear and angular velocity of the end > effector. > As far as i know this will require modification of interface. > How to describe velocities in the same manner like orientation ? > How to add it to interface ? > Velocities should be part of limb_data or be available on request ? > > 2009/6/21 Geoff > > > The limb interface uses the standard method of specifying orientation of > an end effector. The two vectors used are the approach vector and the > orientation vector. The approach vector is a vector that runs down the > length of the end effector in its direction of approach, i.e. it points > where the end effector is pointing. The orientation vector is > perpendicular to the approach vector, usually in the same horizontal > plane in end effector space. It is used to define the end effector's > rotation around the axis that is parallel to the approach vector. > Usually, a third vector is given as well. This is the normal vector. It > is perpendicular to both the approach and orientation vectors. However, > because it can be calculated using the cross product of the other two > vectors, there is no need to transmit it. All vectors extend from the > origin of the end effector, that is, the final joint before it. > Together, they also define the three axes of the end effector coordinate > space. > > As an example, think of your hand. If your hand is straight, then there > is a straight line running down your lower arm and through your hand. > The approach vector extends from your wrist out through your hand along > this line. Hold your thumb out at a right angle to your hand, keeping it > flat in the same plane as your fingers. The orientation vector runs from > your wrist out either in the same direction as your thumb or in the > opposite direction, depending on which hand you're looking at and > whether you're using a right- or left-handed coordinate system, and > perpendicular to the line down your arm. The normal vector will run from > your wrist perpendicular to both of the other two. Typically it will be > defined to point "up." > > Now try rotating your hand around your wrist along the line that runs > down your arm. The orientation and normal vectors will move, while the > approach vector stays the same. If you point your hand downwards, the > orientation vector stays the same while the normal and approach vectors > move. > > If you want to make a rotation matrix from these three vectors, you can > do it by using dot products to calculate their angles around some other > coordinate space's axes. > > Geoff > > Konrad Banachowicz wrote: > > Hi all, > > I'm writing IK driver for manipulator and I have few questions about > > limb interface. > > Why orientation is discribed with two vectors instead of > player_pose3d_t ? > > How exactly these vectors describe orientation, how to create rotation > > matrix from them? > > > > ------------------------------------------------------------------------------ > Are you an open source citizen? Join us for the Open Source Bridge > conference! > Portland, OR, June 17-19. Two days of sessions, one day of > unconference: \$250. > Need another reason to go? 24-hour hacker lounge. Register today! > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > _______________________________________________ > Playerstage-users mailing list > Playerstage-users@... > > https://lists.sourceforge.net/lists/listinfo/playerstage-users > > > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------------ > Are you an open source citizen? Join us for the Open Source Bridge conference! > Portland, OR, June 17-19. Two days of sessions, one day of unconference: \$250. > Need another reason to go? 24-hour hacker lounge. Register today! > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > > > ------------------------------------------------------------------------ > > _______________________________________________ > Playerstage-users mailing list > Playerstage-users@... > https://lists.sourceforge.net/lists/listinfo/playerstage-users ```
 Re: [Playerstage-users] Limb interface From: Konrad Banachowicz - 2009-06-22 17:02:21 Attachments: Message as HTML ```ok, but this way i can use position3d to control end-effector position instead of limb. So why we need limb interface, i think there should be single interface to control end effector. Limb should provide full control over end effector. Maybe position3d should be used instead ? 2009/6/22 Geoff > If you want to control the linear and angular velocity of the end > effector, you should make your driver provide a position3d interface as > well. > > Geoff > > Konrad Banachowicz wrote: > > Thanks for explanation. > > I have few more questions. > > I want to be able to get and set linear and angular velocity of the end > > effector. > > As far as i know this will require modification of interface. > > How to describe velocities in the same manner like orientation ? > > How to add it to interface ? > > Velocities should be part of limb_data or be available on request ? > > > > 2009/6/21 Geoff > > > > > The limb interface uses the standard method of specifying orientation > of > > an end effector. The two vectors used are the approach vector and the > > orientation vector. The approach vector is a vector that runs down > the > > length of the end effector in its direction of approach, i.e. it > points > > where the end effector is pointing. The orientation vector is > > perpendicular to the approach vector, usually in the same horizontal > > plane in end effector space. It is used to define the end effector's > > rotation around the axis that is parallel to the approach vector. > > Usually, a third vector is given as well. This is the normal vector. > It > > is perpendicular to both the approach and orientation vectors. > However, > > because it can be calculated using the cross product of the other two > > vectors, there is no need to transmit it. All vectors extend from the > > origin of the end effector, that is, the final joint before it. > > Together, they also define the three axes of the end effector > coordinate > > space. > > > > As an example, think of your hand. If your hand is straight, then > there > > is a straight line running down your lower arm and through your hand. > > The approach vector extends from your wrist out through your hand > along > > this line. Hold your thumb out at a right angle to your hand, keeping > it > > flat in the same plane as your fingers. The orientation vector runs > from > > your wrist out either in the same direction as your thumb or in the > > opposite direction, depending on which hand you're looking at and > > whether you're using a right- or left-handed coordinate system, and > > perpendicular to the line down your arm. The normal vector will run > from > > your wrist perpendicular to both of the other two. Typically it will > be > > defined to point "up." > > > > Now try rotating your hand around your wrist along the line that runs > > down your arm. The orientation and normal vectors will move, while > the > > approach vector stays the same. If you point your hand downwards, the > > orientation vector stays the same while the normal and approach > vectors > > move. > > > > If you want to make a rotation matrix from these three vectors, you > can > > do it by using dot products to calculate their angles around some > other > > coordinate space's axes. > > > > Geoff > > > > Konrad Banachowicz wrote: > > > Hi all, > > > I'm writing IK driver for manipulator and I have few questions > about > > > limb interface. > > > Why orientation is discribed with two vectors instead of > > player_pose3d_t ? > > > How exactly these vectors describe orientation, how to create > rotation > > > matrix from them? > > > > > > > > > ------------------------------------------------------------------------------ > > Are you an open source citizen? Join us for the Open Source Bridge > > conference! > > Portland, OR, June 17-19. Two days of sessions, one day of > > unconference: \$250. > > Need another reason to go? 24-hour hacker lounge. Register today! > > > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > > _______________________________________________ > > Playerstage-users mailing list > > Playerstage-users@... > > > > https://lists.sourceforge.net/lists/listinfo/playerstage-users > > > > > > > > ------------------------------------------------------------------------ > > > > > ------------------------------------------------------------------------------ > > Are you an open source citizen? Join us for the Open Source Bridge > conference! > > Portland, OR, June 17-19. Two days of sessions, one day of unconference: > \$250. > > Need another reason to go? 24-hour hacker lounge. Register today! > > > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Playerstage-users mailing list > > Playerstage-users@... > > https://lists.sourceforge.net/lists/listinfo/playerstage-users > > > ------------------------------------------------------------------------------ > Are you an open source citizen? Join us for the Open Source Bridge > conference! > Portland, OR, June 17-19. Two days of sessions, one day of unconference: > \$250. > Need another reason to go? 24-hour hacker lounge. Register today! > > http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org > _______________________________________________ > Playerstage-users mailing list > Playerstage-users@... > https://lists.sourceforge.net/lists/listinfo/playerstage-users > ```