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+--- Thread: Help Documentation is incomplete for a beginner at 6.4 (/thread-3541.html)
Documentation is incomplete for a beginner at 6.4 - RameezSafdar - 29-07-2022
I have imported Obi rope 6.4 into my project from asset store and documentation seems to be incomplete. I searched youtube videos and all of them are so old that they can not cater a new user who uses obi for 1st time.
I need help to create a simple rope and then I need to elongate / shorten it on runtime. How can I do this? Can someone help me with it?
I created a simple rope by looking at example scenes, my rope doesnt collide, and if somehow i manage to make a visible rope in editor, in play mode that visual rope is no more there even though game object is.
How do i deal with this?
RE: Documentation is incomplete for a beginner at 6.4 - josemendez - 29-07-2022
(29-07-2022, 11:57 AM)RameezSafdar Wrote: I have imported Obi rope 6.4 into my project from asset store and documentation seems to be incomplete. I searched youtube videos and all of them are so old that they can not cater a new user who uses obi for 1st time.
Hi!
Documentation is up to date, and rather extensive:
http://obi.virtualmethodstudio.com/manual/6.3/
If you feel like any part of it is incomplete, please let me know so that I can cover more areas.
Videos in the web are also up to date (may be minor differences in UI in some videos):
http://obi.virtualmethodstudio.com/videos.html
Specifically, the video on how to create a basic rope was made with Obi 6.2 which is identical to 6.4 in most aspects:
https://www.youtube.com/watch?v=ajvNojymPzI&list=PLnCR8_XCOgrYqv3fhBjG9K0Kns3UmsJ8B
(29-07-2022, 11:57 AM)RameezSafdar Wrote: I need help to create a simple rope and then I need to elongate / shorten it on runtime. How can I do this? Can someone help me with it? I created a simple rolpe
If you already created a simple rope, just add a ObiRopeCursor component on it and call its ChangeLength() method at runtime. There's an entire page in the manual dedicated specifically to this, "Changing rope length at runtime":
http://obi.virtualmethodstudio.com/manual/6.3/ropecursor.html
There's also some included sample scenes that do this, see the "Crane" one for example.
(29-07-2022, 11:57 AM)RameezSafdar Wrote: my rope doesnt collide,
Make sure that:
- You've added ObiColliders to the objects you want it to collide against. See the manual page about "collisions":
http://obi.virtualmethodstudio.com/manual/6.3/collisions.html
- Collision constraints are globally enabled in the solver. See the manual page about "solvers":
http://obi.virtualmethodstudio.com/manual/6.3/obisolver.html
(29-07-2022, 11:57 AM)RameezSafdar Wrote: and if somehow i manage to make a visible rope in editor, in play mode that visual rope is no more there even though game object is.
As long as the rope is managed by a solver, it should be visible both in editor and at runtime, since that makes no difference. Also make sure that there's at least one updater component to tick the solver's simulation. To understand the relationship between updaters,solvers and actors in Obi, see:
http://obi.virtualmethodstudio.com/manual/6.3/bigpicture.html
Keep in mind that Obi is a rather large and complex engine. It will take a while to learn how to use it, specially if you're unfamiliar with physics simulation and 3D in general.
Let me know if I can be of further help!
RE: Documentation is incomplete for a beginner at 6.4 - RameezSafdar - 29-07-2022
This was very helpful, thank you so much for this. I have successfully created the rope and have also learnt about particle collision. I am increasing the length of my rope on runtime using rope cursor. Unfortunately, certain points of my rope does not collide with other objects and those parts of rope which do collide, they are very jittery. How can i solve it? Tried everything i could, applied obi collider, turned on surface collisions on rope etc. Nothing seems to help.
RE: Documentation is incomplete for a beginner at 6.4 - AlphaDen - 29-07-2022
Hey Team,
The asset is really cool but I still have 1 similar doubt. When using Obi Roper Cursor to change the length. It either reduces the rope at the start or end. My case is simple. I have a rope across 5 different Obi Particle Attachment points(Type: Static). I want to maintain the same elasticity of the rope. Like when 2 points are close together or far apart. Is there a way to change the length of the whole rope? Cause now it feels like it is either changing the length of the first 2 control points or the last 2 and it also doesn't seem to work all the time. Not sure why.
My case is simple. I have 5 Obi particle attachment points and I want the rope to look the same(elastic but kinda stiff) and looks the same equally across all Obi particle attachment points.
The Crain example is not apt since it extends the rope only at the end.
RE: Documentation is incomplete for a beginner at 6.4 - RameezSafdar - 29-07-2022
(29-07-2022, 06:50 PM)AlphaDen Wrote: Hey Team,
The asset is really cool but I still have 1 similar doubt. When using Obi Roper Cursor to change the length. It either reduces the rope at the start or end. My case is simple. I have a rope across 5 different Obi Particle Attachment points(Type: Static). I want to maintain the same elasticity of the rope. Like when 2 points are close together or far apart. Is there a way to change the length of the whole rope? Cause now it feels like it is either changing the length of the first 2 control points or the last 2 and it also doesn't seem to work all the time. Not sure why.
My case is simple. I have 5 Obi particle attachment points and I want the rope to look the same(elastic but kinda stiff) and looks the same equally across all Obi particle attachment points.
The Crain example is not apt since it extends the rope only at the end.
I think if you change cursor Mu and source mu at obi rope cursor, you will achieve the effect you want
RE: Documentation is incomplete for a beginner at 6.4 - josemendez - 01-08-2022
(29-07-2022, 06:50 PM)AlphaDen Wrote: Hey Team,
The asset is really cool but I still have 1 similar doubt. When using Obi Roper Cursor to change the length. It either reduces the rope at the start or end.
Just place the solver at a different point in the rope, other than the start or the end. This is done by setting the cursor's "mu" property. See:
http://obi.virtualmethodstudio.com/manual/6.3/ropecursor.html
(29-07-2022, 06:50 PM)AlphaDen Wrote: it also doesn't seem to work all the time. Not sure why.
Make sure the blueprint has enough pooled particles to increase the length of the rope. The default is 100, once the cursor has added 100 extra particles there will be none left in the pool and the rope will not extend further. See "pooled particles" in the blueprint:
http://obi.virtualmethodstudio.com/manual/6.3/ropesetup.html
(29-07-2022, 06:50 PM)AlphaDen Wrote: The Crain example is not apt since it extends the rope only at the end.
Nope, the Crane example extends the rope at the middle.
Note that when using a ObiRopeExtrudedRenderer to draw the rope, the mesh UV coordinates can be anchored at any point in the rope, but they must be continuous (see "UV Anchor" property of the extruded renderer).
This means that while you can physically insert new particles in the rope at any point along its length, the texture coordinates may be anchored at a different point, giving the impression that the rope is being resized in a different way. This is the trick used by the Crane example: the rope is extended in the middle, but the UV coords are anchored at one end, so the rope looks as if resized from one end. This is just a visual illusion: the texture coordinates "slide" across it to achieve this.
kind regards,
RE: Documentation is incomplete for a beginner at 6.4 - josemendez - 01-08-2022
(29-07-2022, 05:35 PM)RameezSafdar Wrote: Unfortunately, certain points of my rope does not collide with other objects and those parts of rope which do collide, they are very jittery. How can i solve it? Tried everything i could, applied obi collider, turned on surface collisions on rope etc. Nothing seems to help.
What kind of colliders are they colliding against? what are your collision constraint settings (iteration count, relaxation factor, etc)?
To debug collisions, it's usually useful to add a ObiParticleRenderer to the rope. This lets you visualize particles, which can be helpful to see the actual shapes being used for collision detection.