Tons of problems trying to simulate simple rope without elasticity

[josemendez]

Well.. This definitely much better comparing what I made, but also with some weird things. The rope stops pretty often in such poses 

That's probably because the solver's sleep threshold is a tad too high, reducing it will allow rope particles to continue moving even if they have very little energy:
http://obi.virtualmethodstudio.com/manua...olver.html

Sleep threshold: Any particle with a kinetic energy below this value will be freezed in place. This is useful when you don´t want minuscule variations in velocity or force to perturb an actor, making it look like its jittering or moving very slowly.

but the funniest is how it deforms like a wave when you drag it. I found that adding much more mass to paperclip (1kg instead of 0.1f) the result is much better.

This is the expected and intended behavior: the "waves" are energy traveling trough the rope. Keep in mind that dragging a transform happens in Update(), but the simulation takes place in FixedUpdate(). FixedUpdate() is called at a different frequency than Update(), so the rope sees the cylinder it is attached teleport between frames in stop-and-go fashion. These small jerky movements are translated as waves traveling trough the rope.

Increasing the mass of the paperclip tenses the rope up faster, so the frequency of the waves will increase and become less noticeable mainly due to the temporal resolution not being high enough to see fast vibrations. Damping also plays a role in this.

Btw, it would be veeeery helpful if you add more sample scenes with a different materials simulation.

The Crane and FreightLift scenes have easily bendable ropes, the RopeShowcase has ropes with various bending parameters, the rope cutting scene has somewhat intermediate stuff. You also have examples of chains, nets, etc. Each scene uses quite different parameters. If there's any parameter combination in particular that you'd want to see among the examples let me know!

For example, in your package you attached I see that you activated all the constraints (except chain) in ObiSolver component, while your Rope package sample scenes have just couple of them enabled with a different params. I believe not all of these constraints are required - I didn't test much but disabling some of them didn't affect to the rope behaviour at all.

The manual introduction contains a list of all constraint types and indicates which actors use each one and what for:
http://obi.virtualmethodstudio.com/manua...rainttypes

For instance:

Distance constraints: [...]These are responsible for the elasticity of cloth and ropes.
Bend constraints: [...]These are used to make cloth and ropes resistant to bending.
Tether constraints: [...]These constraints are used to reduce stretching of cloth.
Skin constraints: [...]Skin constraints are used to keep skeletally animated cloth close to its skinned shape.
Stretch/shear constraints: [...]These are used by rods and bones.

...etc

Then the individual page for each constraint type describes where they are used and how they work.

Ropes only use distance and bend constraints:
http://obi.virtualmethodstudio.com/manua...aints.html
http://obi.virtualmethodstudio.com/manua...aints.html

You can also see that distance and bend are the only constraint types that appear in the ropes' inspector.
Rods for instance, use stretch/shear, bend/twist and chain constraints:

http://obi.virtualmethodstudio.com/manua...aints.html
http://obi.virtualmethodstudio.com/manua...aints.html
http://obi.virtualmethodstudio.com/manua...aints.html