Hi Gianni, ChBodyEasyCylinder creates a body representing a solid cylinder centered at the body COM and aligned along the specified axis of the COM frame. The body mass and inertia is set automatically assuming the cylinder is solid and has constant density. AddCylinderGeometry allows you to attach a cylindrical shape (for collision and, optionally also visualization) to an existing body. This utility function allows you to position this cylinder arbitrarily relative to the body COM. This is what “Position on body” represents (a translation of the cylinder shape from the body COM and expressed in the body COM frame. It is your responsibility to construct the body (including setting its inertial properties).
Note that ChBody::SetPos() sets the origin of the body COM frame relative to the absolute coordinate. It is important to understand well all the frames involved and in what frame various quantities are relative to and expressed in. See for example the first figure on this Chrono documentation page: https://api.projectchrono.org/development/collisions.html#collision_models_shapes. --Radu From: projectchrono@googlegroups.com <projectchrono@googlegroups.com> On Behalf Of Gianni Curti Sent: Wednesday, November 20, 2024 7:26 PM To: ProjectChrono <projectchrono@googlegroups.com> Subject: [chrono] Difference between ChBodyEasyCylinder and AddCylinderGeometry Hi, I have a question regarding the difference between the commands "ChBodyEasyCylinder" and "AddCylinderGeometry". For what I have understood, the first one automatically calculates the mass and inertia of a body depending on the sizes and density given, while the second one provides only the collision shape of a cylinder (neither mass nor density if they are not manually given). However, I saw that there is the possibility of assigning the "Position on body" when using "AddCylinderGeometry" through a ChVector3d but the result is pretty different from what I obtain by using "SetPos" when I also apply a rotation to the body. What does this command do exactly? Thank you in advance for yout patience and kindness. Best Regards Gianni -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to projectchrono+unsubscr...@googlegroups.com<mailto:projectchrono+unsubscr...@googlegroups.com>. To view this discussion visit https://groups.google.com/d/msgid/projectchrono/10d9deb5-26b4-4ebe-a37b-41e1fdec1037n%40googlegroups.com<https://urldefense.com/v3/__https:/groups.google.com/d/msgid/projectchrono/10d9deb5-26b4-4ebe-a37b-41e1fdec1037n*40googlegroups.com?utm_medium=email&utm_source=footer__;JQ!!Mak6IKo!LZqh0A2nDt0mRsewyds4KGDxAMXR0yiR6uVrKzMnUhhgRxnzpGL_G-mItt0BNX6E85FtgDOxibRx1YgTxMNb$>. -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to projectchrono+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/projectchrono/CH3PPF46CDC2185FD44FC817433DE962EEAA72A2%40CH3PPF46CDC2185.namprd06.prod.outlook.com.
