Hello, I’m trying to reproduce the setup of an experiment I’m doing with Poppy torso in VREP.
To do that, I need to add an object in Poppy’s right hand (the object is stuck in Poppy’s hand and cannot possibly fall), move Poppy and track the object position.
However I can’t find a way to make it work. I tried making the object a child of Poppy’s forearm, make it respondable and static (maybe the wrong part as I don’t know any other way to stick it in the hand), but when I launched pypot to control the robot, I got a VrepIOErrors: No value. I’m running the robot using pypot.vrep.from_vrep method.
The problem is I need the object in Poppy’s hand to be both stuck in the hand and collidable with the world.
Just tried to add a sphere attach to r_forearm_respondable and I don’t have any pypot error.
Can you give your scene (.ttt)
EDIT : if you add a join in the vrep scene and not in the config file, maybe it can raise issues… Anyway, need to test with your vrep scene.
Actually, I found a way to do what I need on the Bubblerob tutorial. Here is a picture of the scene I got:
I saw that Force sensors can be used to link two objects together. However, I’m not entirely satisfied as the tip of the stylet (the object in the robot’s right hand) moves slightly when I lower the right arm and the stylet is touching the tab.
I don’t know if there is a way to fix definitely the pose of an object relatively to another (the object being respondable and dynamic).
Stylet ok:
Tip of the stylet moving inside the stylet cylinder:
Great, Poppy torso can write 
Remenber that something like a static join can also be used, but really not sure.
I tried again using joints and it gives me the same problem. The tip of the stylus is moving when I would like it to remain in the stylus cylinder. Is there any way to prevent the stylus pieces from moving when Poppy is forcing and relay the force straight to Poppy arms’ joints?