As I said, the motivation is to help teachers interested in building simple simulations for Physics teaching but would not go up the high learning curve for Linden Scripting Language. TATI is able to translate simple Logo-like TATILogo commands into different kinds of objects each one following different physical laws.
There are 6 types of object available: NOROBJECT, GEOOBJECT, VELOBJECT, ACCOBJECT, NEWOBJECT, PHYOBJECT.
TATI listens to commands on channel 33 from its owner.
Here I show a few examples of creating different types of objects.
Example 1 - NOROBJECT
In the first video, I order TATI to create an object dubbed B1. By default, it will be of NOROBJECT type, which is simply the basic non-physical SL object.
It’s insensitive to SL gravity and, therefore, will float at the position where it was rezzed.
It can be moved like a Papert's Geometry Turtle with TATILogo commands FORWARD and BACKWARD.
To be able to distinguish the various objects, besides the label TATI puts above the object, the user may want to give them different colours. For example, I commanded TATI to change its default color to blue.
The TATILogo commands given were simply:
Example 2 - VELOBJECT
In the second video, I order TATI to create a VELOBJECT, which somehow corresponds to Papert’s ‘Velocity Turtle’. It float as well but do not understand position changing commands like FORWARD and TATI sends error messages about that to the user.
In analogy to it, however, there are state-changing TATILogo commands such as SPEEDUP to increase the object present speed (an scalar quantity) in the direction it is heading.
There is also the command SETVEL, corresponding to Papert’s SETVELOCITY command, to set its velocity (a vectorial quantity) which can have any direction.
The TATILogo commands given were:
Example 3 - PHYOBJECT
In the third video, I ordered a PHYOBJECT, the basic physical SL object.
As it is subject to SL gravity and dynamics, it falls down to the ground (in this case, right through the hat which was providentially made immaterial to avoid collisions) and rolls the inclined ground down until it finds some obstacle.
Both FORWARD and SPEEDUP TATILogo commands fail because PHYOBJECTs accept only commands that apply mechanical forces, impulses and torques to it.
Firstly I apply a rotational impulse to it to turn it to a convenient position.
Then, I apply a force to it which will cause it to accelerate until the applied force is set to zero. An increase in speed is clearly visible.
If there were not dynamical effects of interaction with the ground, the object, free from forces, would then keep going with constant velocity. Instead, it stops moving.
Now the TATILogo commands were: