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Tons of problems trying to simulate simple rope without elasticity
#8
(14-01-2022, 03:44 PM)Romahaaa Wrote: UPDATE!
Well, seems I found one of the main problems here - in your package the size of objects are not realistic, it's about x50 time bigger then real world size. In my case the rope is ~12cm, paper clip ~3cm, pencil ~15cm. I created rope blueprint according to the real size, so this means the distance between start and end points (attachment points) was ~12cm. Using Particle renderer I see that there are only 2 particles in the real world size rope using the parameters from your scene.
The only way to add more particles is decreasing blueprint thickness and set decimation to 0 but after reaching same particles count for the same distance, I see that the rope behaviour become pretty different.
Another approach I found to fit your last example to my real world size scene is to scale down the ObiSolver transform to 0.02. The only issue in that case that paperclip doesn't rotates, only when collides with a surface.
Please clarify - why these 2 approaches doesn't behave similar way? Does it mean that rope itself had to be bigger initially?

Yes, everything is way bigger than in real life in that scene as I pointed out:

“Also the scale of the scene is quite large: that clip is definitely not as small as a real-world clip, but based on the grid seen in your original video I think it's pretty close to yours.”

I took your original video as reference, there the clip is around half a grid cell (which I thought meant its intended size was half a meter long or so). Seemed weird to me so that’s why I commented on that, not sure if my interpretation of your scene was correct.

Scaling the solver does not scale the rope: it scales the simulation space, that’s very different.
Think about an object moving at 10 m/s: if you make the object half its size, it still moves at 10 m/s.  However if you keep the size of the object and scale the space down by 50%, the object will not only look smaller but appear to move at 5 m/s for any external observer.

In your case, making a thin rope using real world units is the best approach imho.
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Messages In This Thread
RE: Tons of problems trying to simulate simple rope without elasticity - by josemendez - 15-01-2022, 12:24 AM