Name: Rotating Cafe Wall Illusion

Image:

Rotating Cafe Wall

Description: The classic flat museum exhibit Cafe wall illusion is wrapped around a rotating cylinder in Second Life. Even though all the horizontal lines are parallel to each other they appear to converge or diverge. As the cylinder rotates they appear to converge or diverge forever rather like the infinitely ascending or descending staircases in an Escher drawing.

Creator: Patio Plasma April 2006.

Location: Splo Main,

Midnight City                Teleport here first then walk to the exhibit. http://slurl.com/secondlife/Midnight%20City/177/58/26

Graphics:

cafe wall texture 256x256
This is the texture used in the exhibit, shown here as 256x256.

For a 512x512 texture click here.

Drag the texture from inventory onto the outer surface of a cylinder.

Lessons:

Rotation

This exhibit contains a simple script which makes it rotate. The main command is targetomega

default
{ state_entry() { llTargetOmega(<0,0,1>, 1, 1); }}

In this script the <0,0,1> is a vector <x,y,z> which specifies rotation about the z axis. And the 1 following the vector is the rotation rate in radians per second (multiplied by the magnitude of the rotation axis vector), the last 1 is the torque if the rotating object is physical, stop rotation by setting this final parameter to 0.

For more details go here  LSL Wiki Target Omega

Give Inventory

When you touch the exhibit you will be offered a notecard by the following inventory giver script


// GiveNotecard in Inventory by Sploco

string gNotecardName;

default
{
state_entry()
{

gNotecardName = llGetInventoryName(INVENTORY_NOTECARD,0);
}

touch_start(integer touched)
{
llGiveInventory(llDetectedKey(0),gNotecardName);  // llDetectedKey(0) gets the identification number of the avatar who touched the prim.
}


//if inventory is changed reset the script
changed(integer change)
{
if (change & CHANGED_INVENTORY)
{
llResetScript();
}
}
}

llDetectedKey(0)  gives the identification number of the avatar that will receive the notecard from inventory.

Comments: This was the first exhibit made for the 'Splo. When Kua Patten saw this exhibit in Second Life he considered it as a 3-d prototype for an exhibit in the real world. A working prototype of this exhibit was built in the real Exploratorium making this one of the first exhibits to be developed in Second Life and realized in a real world museum.

In 2008 Heureka, a Science Museum in Finland made a full scale version of this exhibit. See their you tube video here http://www.youtube.com/watch?v=lLjG0OiKopM

The first second life exhibit copied from the Splo into a real life museum other than the Exploratorium.

 

Patio Plasma

Copyright 2007

Updated 28 May 2007