Models

Overview

As a 3d application platform, models are one of the most important content types in OpenSimulator.

There are currently three forms of models supported by OpenSimulator:

• Parametrized Primitives (often called "prims")
• Sculpted Primitives (often called "sculpts" or "sculpties")
• Vertex Meshes

Each has their own strengths, drawbacks, and quirks.

Creation Process

Parametrized primitives can be created in world with build functionality.

Sculpted primitives are defined by a special bitmap image which can be created with 3d modeling programs which support sculptures.

Mesh files can be created in many 3d modeling programs such as Blender, 3DS Max, Maya, etc. Note that while mesh support within viewers is becoming more ubiquitous, it is not universal.

Format Breakdown

Generally speaking, parametric primitives are best suited for simple geometric objects and for allowing collaborative in-world building. They are by far the most reliable and understood of the three formats. However, primitives contain a great deal of extraneous geometry used to enable their parametric behavior (in-world building/deformation with sliders).

Sculpted primitives are ideal for creating organic shapes (such as trees, body parts, sculpted surfaces) when you want to be sure of backwards compatibility. Unfortunately, they have a high amount of geometric detail which cannot be altered by the creator and can be difficult to texture properly.

Mesh files are excellent for experienced content creators, especially those coming to OpenSimulator from other 3d platforms. When correctly utilized, they can have as much expressiveness as sculpted primitives and more efficient geometry than parametric primitives. The learning curve for mesh file creation is somewhat steeper, and there is more ways to get in trouble using it.