Sorry your browser is not supported!

i am trying to figure out the best way to go about modelling molecules

each molecule would have a number of atoms (rigid spheres) and bonds (joints)

For a particular atom, all of the joints on that atom would need to try to get as far away from eachother as possible (that is what gives molecules their shapes)

take ethane for example:



So for ethane, each carbon atom would form a tetrahedral shape with its hydrogens and other carbon, but the hydrogens would be free to rotate around perpendicular to the carbon-carbon bond

also the bonds would need to "jiggle" a little bit

what kind of darkphysics joint should i apply to get this sort of effect? the help files don't really specify all of the commands for setting joints

this is what the help files don't clarify in particular:

can someone explain these joint settings?

phy set sphere joint local anchor ID, index, x#, y#, z#
phy set sphere joint local axis ID, index, x#, y#, z#
phy set sphere joint global anchor ID, index, x#, y#, z#
phy set sphere joint global axis ID, index, x#, y#, z#
phy set sphere joint swing axis ID, x#, y#, z#
phy set sphere joint swing limit ID, value#, restitution, hardness#
phy set sphere joint twist limit ID, low#, high#
phy set sphere joint twist spring ID, target#, spring#
phy set sphere joint swint spring ID, target#, spring#
phy set sphere joint spring ID, target#, spring#
phy set sphere joint projection ID, mode, distance#

i think you are looking for a cylindrical joint. where you have rotation along the axis but only lateral movement up and down the axis.

straight from the help file tutorials

The command to make prismatic joints is phy make cylindrical joint and it takes several parameters:



joint ID, joints have unique ID numbers, when making a joint it is important to provide the command with an ID number that has not been used, if you do not do this the command will fail
rigid body A, this is the ID number of the first rigid body that is to be used in the joint
rigid body B, this is the ID number of the second rigid body that is to be used in the joint
x#, this parameter controls where the cylindrical joint is positioned in world space on the X axis
y#, this parameter controls where the cylindrical joint is positioned in world space on the Y axis
z#, this parameter controls where the cylindrical joint is positioned in world space on the Z axis
axis x#, allowable translational movement on X axis, if no movement is permitted use a value of 0.0, for movement use a value to relate how much distance is allowed for movement on X axis e.g. 10.0
axis y#, allowable translational movement on Y axis, if no movement is permitted use a value of 0.0, for movement use a value to relate how much distance is allowed for movement on Y axis e.g. 10.0
axis z#, allowable translational movement on Z axis, if no movement is permitted use a value of 0.0, for movement use a value to relate how much distance is allowed for movement on Z axis e.g. 10.0