Difference between revisions of "Primitive"

Revision as of 11:31, 26 April 2010

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This article is about primitives. For LSL related information, see Category:LSL Prim.

A primitive, or prim, is a single-part object. Multi-part objects will have multiple parts ("prims").

In Second Life, virtual physical objects such as cars, houses, jewelry, and even less obvious things like hair and clothing are made out of one or more prims. Objects made from prims are usually created in-world using the built-in object editing tool. This tool is used for all sorts of 3D modeling in Second Life, playing the same role as 3D Max, Maya, or Blender, but customized for the Second Life way of doing things.

Each prim is represented by a set of parameters, including shape/type, position, scale/size, rotation, cut, hollow, twist, shear, etc. These parameters are sent from a server to the viewer running on the resident's desktop, where the local video card is used to render the visual appearance of everything. (Rendering on the server would probably create a much higher amount of network traffic.)

The color, texture, bumpiness, shininess, and transparency of prims can also be adjusted, and images (textures) can be applied to each surface (face/side) of a prim to change its appearance. Box, cylinder, and prism prim shape types can also be made flexible.

Prims can be linked together into link sets. They can also be attached to avatars, but this process is separate from (thought similar to) linking.

In the Viewer source code, primitives are implemented in LLPrimitive, with vertex generation performed in LLVolume and rendering in LLVOVolume.

Shape types

There are eight primitive shape types:

box: all kinds of rectangular shapes
cylinder: round tables, floors, long pipes
prism: a box with one very small face
sphere: can be used for ellipsoids of all shapes
torus: most complex, can be modified in many exotic ways
tube: another form of hollow cylinder
ring: another variant of torus
sculpted: new as of 2007, used for highly variable organic shapes

Properties

Mass

The mass of a prim is a function of it's volume, different prim shapes have different volumes thus different masses.

Mass Lab demonstrates how different shapes have different masses.

Survival

The survival of properties depends upon the type of the property and what happens to the object.

**Property survival**
Property	Script Set Not Running	Script Removal	Take unscripted and re-rez	Shift-drag-copy
Sit Target	Yes	Yes	Yes	?
Particles	Yes	Yes	Yes	?
Floating Text	Yes	Yes	Yes	No
Spin	Yes	No	?	?
Collision Sound	Yes	Yes	?	?
Looped Sound	Yes	Yes	Yes	No
Remote Script Access Pin	Yes	Yes	?	?
Light	Yes	Yes	Yes	Yes
Status	Yes	Yes	Yes	Yes
Buoyancy	?	No	No	?
Texture Animation	Yes	Yes	Yes	No

It should be noted that when a script (in an object) moves from one simulator into another while being set as "Not Running" (either by llSetScriptState or via the checkbox in the script editor) the script's state will be lost. See SVC-1853 for details.

Materials

There are seven primitive material types that determine things like friction and default collision sound:

stone
metal
glass
wood
flesh
plastic
rubber

Help

Basic Prim Creation and Editing

Scripting

Category:LSL_Prim

Video tutorials

External links

Wikipedia: Geometric primitive

@@ Line 39: / Line 39: @@
 # ring: another variant of torus
 # [[sculpt]]ed: new as of 2007, used for highly variable organic shapes
-----
-*Setting a different type can effect more than the shape. E.g. The [[llGetMass|mass]] can change in a prim that has <u>only</u> the type changed.
-<lsl>// A simple study of how mass is effected by prim shape/types. The X,Y,Z size is not changed but the mass does.
-// Material type and/or physics seem to not effect mass.
+==Properties==
+==== Mass ====
+The [[mass]] of a prim is a function of it's volume, different prim shapes have different volumes thus different masses.
+* [[Mass Lab]] demonstrates how different shapes have different masses.
-default
+==== Survival ====
-{
-    state_entry()
-    {
-        llSetScale(<1.0, 1.0, 1.0>); // 1 meter cubed
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_BOX,
-        PRIM_HOLE_DEFAULT, <0.0, 1.0, 0.0>, 0.0, <0.0, 0.0, 0.0>, <1.0, 1.0, 0.0>, <0.0, 0.0, 0.0>]);
-        llOwnerSay("BOX: " + (string)llGetMass()); // Output: Object: 10.000000
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_CYLINDER,
-        PRIM_HOLE_DEFAULT, <0.0, 1.0, 0.0>, 0.0, <0.0, 0.0, 0.0>, <1.0, 1.0, 0.0>, <0.0, 0.0, 0.0>]);
-        llOwnerSay("CYLINDER: " + (string)llGetMass()); // Output: Object: 10.000000
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_PRISM,
-        PRIM_HOLE_DEFAULT, <0.0, 1.0, 0.0>, 0.0, <0.0, 0.0, 0.0>, <1.0, 1.0, 0.0>, <0.0, 0.0, 0.0>]);
-        llOwnerSay("PRISM: " + (string)llGetMass()); // Output: Object: 10.000000
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_SPHERE,
-        PRIM_HOLE_DEFAULT, <0.0, 1.0, 0.0>, 0.0, <0.0, 0.0, 0.0>, <0.0, 1.0, 0.0>]);
-        llOwnerSay("SPHERE: " + (string)llGetMass()); // Output: Object: 5.235988
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_TORUS,
-        PRIM_HOLE_DEFAULT, <0.0, 1.0, 0.0>, 0.0, <0.0, 0.0, 0.0>, <1.0, 0.5, 0.0>, <0.0, 0.0, 0.0>, <0.0, 1.0, 0.0>, <0.0, 0.0, 0.0>, 1.0, 0.0, 0.0]);
-        llOwnerSay("TORUS: " + (string)llGetMass()); // Output: Object: 5.235988
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_TUBE,
-        PRIM_HOLE_DEFAULT, <0.0, 1.0, 0.0>, 0.0, <0.0, 0.0, 0.0>, <1.0, 0.5, 0.0>, <0.0, 0.0, 0.0>, <0.0, 1.0, 0.0>, <0.0, 0.0, 0.0>, 1.0, 0.0, 0.0]);
-        llOwnerSay("TUBE: " + (string)llGetMass()); // Output: Object: 5.235988
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_RING,
-        PRIM_HOLE_DEFAULT, <0.0, 1.0, 0.0>, 0.0, <0.0, 0.0, 0.0>, <1.0, 0.5, 0.0>, <0.0, 0.0, 0.0>, <0.0, 1.0, 0.0>, <0.0, 0.0, 0.0>, 1.0, 0.0, 0.0]);
-        llOwnerSay("RING: " + (string)llGetMass()); // Output: Object: 5.235988
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_SCULPT, "bea82b0f-27c6-730b-fd7f-733f2340b449", PRIM_SCULPT_TYPE_SPHERE] );
-        llOwnerSay("SCULPTED APPLE: " + (string)llGetMass()); // Output: Object: 5.229262
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_SCULPT, "d1b6cc53-ac61-291f-9ce1-dc18170aa6a6", PRIM_SCULPT_TYPE_SPHERE] );
-        llOwnerSay("SCULPTED APPLE STEM: " + (string)llGetMass()); // Output: Object: 5.229262
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_SCULPT, "d962089b-2197-993c-9ec9-4993eb0a95f2", PRIM_SCULPT_TYPE_SPHERE] );
-        llOwnerSay("SCULPTED BANANA: " + (string)llGetMass()); // Output: Object: 5.229262
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_SCULPT, "fb39e9be-0609-2d1e-0988-803d1c04411e", PRIM_SCULPT_TYPE_SPHERE] );
-        llOwnerSay("SCULPTED PLATE: " + (string)llGetMass()); // Output: Object: 5.229262
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_SCULPT, "", PRIM_SCULPT_TYPE_PLANE] );
-        llOwnerSay("SCULPT (no map): " + (string)llGetMass()); // Output: Object: 5.229262
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_SCULPT, "", PRIM_SCULPT_TYPE_CYLINDER] );
-        llOwnerSay("SCULPT (no map): " + (string)llGetMass()); // Output: Object: 5.229262
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_SCULPT, "", PRIM_SCULPT_TYPE_TORUS] );
-        llOwnerSay("SCULPT (no map): " + (string)llGetMass()); // Output: Object: 5.229262
-        llSetPrimitiveParams([PRIM_TYPE, PRIM_TYPE_SCULPT, "", PRIM_SCULPT_TYPE_MASK] );
-        llOwnerSay("SCULPT (no map): " + (string)llGetMass()); // Output: Object: 5.229262
-    }
-}</lsl>
-==Properties==
+The survival of properties depends upon the type of the property and what happens to the object.
 {| {{Prettytable}}
@@ Line 163: / Line 92: @@
 ==Materials==
-There are seven primitive [[material]] types that determine things like friction and sound:
+There are seven primitive [[material]] types that determine things like friction and default [[llCollisionSound|collision sound]]:
 # stone
 # metal