Help ObiRopeCursor for ObiRod

[kripa1415]

Hi  I would need to call ChangeLength for ObiRod. We can do this for ObiRope but I need this feature in ObiRod is it possible ?

[josemendez]

Hi  I would need to call ChangeLength for ObiRod. We can do this for ObiRope but I need this feature in ObiRod is it possible ?

Hi,

Unfortunately not, rods cannot support topological changes. It's one of the main differences with ropes.

kind regards,

[kripa1415]

Oh I see!.
Is it possible to make something similar shown in the video, using ObiRod ?
I attempted and its coming good so far. Stuck in not sure about how to alter rod length 

https://drive.google.com/file/d/1Yo66Ach...sp=sharing

[josemendez]

Oh I see!.
Is it possible to make something similar shown in the video, using ObiRod ?
I attempted and its coming good so far. Stuck in not sure about how to alter rod length 

https://drive.google.com/file/d/1Yo66Ach...sp=sharing

Hi,

Using rods for this is overkill. The spring coils in the video all move in unison and never deviate from a cylinder-like shape, so simulating each individual coil is just a waste of resources: this can just be a texture on a rope.

You could use a procedural texture too, which will give you sharper visuals. I wrote a shader that does this for another user a long time ago, but it only works for the built-in render pipeline. Another user ported it to ShaderGraph. You can find both in this thread:

http://obi.virtualmethodstudio.com/forum...-2706.html

A video of the result:

https://m.youtube.com/watch?v=Vm1COjy9tuU

kind regards,

[kripa1415]

But doing this with rope and procedural texture make it shaky. I want that hard dynamic parabolic nature even when one end of the rod is moving. As you said its following unison cylindrical path. Is it possible to achieve this with rope ? is it possible to make rope harder like this ?

[josemendez]

Is it possible to achieve this with rope ? is it possible to make rope harder like this ?

Yes of course, just set the rope's max bending to zero.

Also attach two control points at each end of the rope (instead of just one) if you want to enforce a specific direction on the attachment. If you attach only one point, the rope will be free to rotate around it. This technique is used in RopeShowcase sample scene to keep the ropes on the left wall perpendicular to it. Also used in the ChainBall scene to make the chain attach to the ball in a specific orientation.

kind regards,

[kripa1415]

I tried to work on the showcase sample by altering its original mechanism. I added one more static object at the other end of rigid rope and added two static end points. Though visually its not looking exactly how I wanted, have a look at the bheaviour, a slightest movement caused the rope to fall and rotate. Its not rigid as in the original video of that game

https://drive.google.com/file/d/1bPxhJUm...sp=sharing

[josemendez]

I tried to work on the showcase sample by altering its original mechanism. I added one more static object at the other end of rigid rope and added two static end points. Though visually its not looking exactly how I wanted, have a look at the bheaviour, a slightest movement caused the rope to fall and rotate. Its not rigid as in the original video of that game

https://drive.google.com/file/d/1bPxhJUm...sp=sharing

Hi,

It falls/rotates due to basic geometry: the 4 points it is attached to are placed in a straight line, unlike in the video of the game.

Attachments are like ball-and-socket joints, so if you put them in a straight line (like a hinge) the object will of course be able to rotate around them. Reorient the attachments so that they point upwards like in the reference video: the rope won't be able to rotate anymore.

kind regards

[kripa1415]

Hi,
 Attached screenshot of the unity scene. You can see the parabolic points are plotted there. If I attach all these points as static connections, yes I agree it creates a parabolic
 rope which remains hard. But what I am trying to achieve is, once its created, as in the original game, If I move one end of the rope, all other points follow and parabolic path
 twists/turn based on the direction of the end point. Here if we make all points as static how can I achieve that? its all going to be static right ? its okay If end points are not going
 to move. But I need the functionality of that game not just the static parabolic path ?

[josemendez]

Hi,
 Attached screenshot of the unity scene. You can see the parabolic points are plotted there. If I attach all these points as static connections, yes I agree it creates a parabolic
 rope which remains hard. But what I am trying to achieve is, once its created, as in the original game, If I move one end of the rope, all other points follow and parabolic path
 twists/turn based on the direction of the end point. Here if we make all points as static how can I achieve that? its all going to be static right ? its okay If end points are not going
 to move. But I need the functionality of that game not just the static parabolic path ?

Hi,

No need to attach all points, that will of course render the rope unable to move. As explained, you only need to attach *two points at each end*, and make sure they’re not all in a straight line.

If your points are numbered from 1 to 7, attach 1 and 2 to one transform and 6 and 7 to another transform. Leave 3,4 and 5 unattached.