Prims can be linked. When several prims are linked, they move together. This is how larger, more complex objects are created in Second Life. To link more than one object in Second Life, select multiple objects and choose the “Link” option from the “Tools” menu. To select more than one object begin by selecting the first object, and then hold down the “Shift” key to select additional objects. The additional objects will be highlighted in yellow. Figure 1.11 shows three “balls” of a snowman about to be linked.

Figure 1.11: Linking a Snowman

    Objects can also be unlinked. Select one, or more prims of the linked object. If you would like to select individual prims of a linked object, the “Edit linked parts” check box on the build window must be checked. Once the prims to be unlinked have been selected, choose the “Unlink” item from the “Tools” menu.

    Not all prims in a linked object are equal. One special prim is called the “root prim”. The root prim is the prim that all movement to the object occurs on. You can think of the root prim as what is actually moving, everything else is simply attached to the root prim. When vehicles and physical objects are created, the root prim becomes very important. All rotation to the compound object is performed on the root prim, the other parts simply follow.

    The root prim is always the last prim that was added to an object. You can easily view the root prim by selecting an object. All non-root prims will show up as cyan. The root prim will show up as yellow. Figure 1.12 shows the snowman. The base of the snowman is the root prim. As you can see, from Figure 1.12, the base of the snowman is a different color to the other parts.

Figure 1.12: The Root Prim of the Snowman