BT Rope is a soft body physics object available within thinkingParticles. The BulletPhysics solver handles all rope dynamics based on two dimensional splines in 3D space. There will be no “volume” to it, every simulation will solely based on the 2D spline deforming and colliding in space. The actual “rope” mesh, will use much more volume than the spline, so rigid body simulations will appear sinking into the rope object. The actual simulation setup has to take care for this side effect (move the object or collide with a dummy slightly bigger).

Compared to all the other operators in thinkingParticles, this operator behaves differently; it creates an actual mesh in a fully procedural way. This soft body mesh is based on two points in space were a spline is drawn between those two points, this object is simulated based on a soft body solver, so it can stretch and spring back.  

ON - (Bool) This input data stream determines whether the operator is considered 'on' or 'off.' You can connect other operators to this input channel such as a Bool Helper to activate/deactivate the whole operator.

Time - (Time) This input data stream is used to define the local time for the operator when the user wants to override the default system time.

From Particle - sets the “From” particle ID that will be used to create a Rope object

To Particle  - sets the “To” particle ID that will be used to create a Rope object

From Position - defines the rope start position in world space. For every new position fed into this operator a new rope object will be created.

To Position  - defines the rope's end position in world space. For every new position fed into this operator a new rope object will be created.

UI Control Parameters - those input data streams are the equivalent of the UI controls, keep in mind that there is no visual indication that an operator is connected to any of those inputs! It might be needless to adjust a value if it gets overwritten by a connected operator.

Born Particle - outputs the currently created rope particle.

From Anchor Index - connect a BTJointData to modify or use the joint attached to this particle

End Anchor Index - connect a BTJointData to modify or use the joint attached to this particle

Before you can see a rope object, you need to supply at least one start point and one end point.  This is usually done by using the operator inputs.

Remember, for every point you feed into the operator a rope will be created automatically.  Use the rope output  along with a RopeData to procedurally set the parameters of this object.

Collision - lets you choose, from the drop down menu, the physics engine solver to use for the rope simulation. All compatible solvers found in the thinkingParticles setup will be automatically listed.

Group - defines the particle group to be used when ropes are created by this operator. Keep in mind -  in the case of BT Rope the rope parameters are automatically created and attached to the particles.

Segmentation - sets the amount of steps (knots) for the spline to be drawn between start and end point.

Linear Stiffness - sets how “springy” or bouncy the rope will be. Lower numbers will create an ultra soft rubber while higher numbers will create a stronger appearing rope. Keep in mind we are talking here soft bodies! The rope will never become as hard as a strip of steel!

Damping - adds a dampening force to the rope stretching. The higher this value the more clay like the rope stretching will appear.

Iteration - sets the amount of intermediate steps the solver will take to simulate the rope system. The higher this value the more accurate the result will be, however the longer it will take to calculate.

Anchor - defines how strong the anchor holds

Rigid - sets the “bounce off” strength for rigid bodies colliding with the rope spline

Fixed Start - when checked the start of the rope will be fixed

Fixed End -when checked it will set the

Threshold - sets the maximum force at which the rope breaks/tears apart

Position - defines the position along the rope were the breaking should occur. A value of 0.5 means the middle part of the rope will break, 0 means it will break at a position were the maximum force occurs.

Zoing - defines the “pre-load” factor for the rope, this controls the tear off effect. a value of 100% will create a maximum pre-loaded spring-back effect.

Anchor Particle Input (From/To) - check either option to specify if an automatic anchor (joint) should be created to attach the rope to its particle. Without any particle position input, the object center will be used automatically to attach the rope to the particle.

None - check this option, to prevent thinkingParticles form creating a mesh

Radial - when checked, a “round” rope mesh will be created.

Constriction - sets the amount of constriction for the rope mesh. A value of 100% will show the maximum constriction.

Rate - sets the amount of constrictions. The higher this value the more constrictions will be visible. To see all of the mesh effects a proper amount of segmentation must be maintained!

Thickness - defines the radius of the rope. The higher this value the thicker the rope will be.

Rotation - rotates the rope around its center.

Sides - sets the amount of segments circumventing the rope.

Steps - defines the mesh resolution along the length of the rope.

Twist - sets how often the rope is twisted around

Autosmooth - check this option to turn on auto-smoothing of the rope mesh

Threshold - sets the angular threshold when to smooth the surface.

Generate Mapping - when checked, mapping coordinates for the rope mesh are created.

MeshMaterialID - sets the material ID to be used for the rope

MeshCapMaterialID - sets the material ID for both caps of the rope (start/end cap)

MeshCutMaterialID - when the rope is cut (break-effect), this defines th4e material ID to be used by the cap surface at each of the cut positions.