Sculpted Prims: 3d Modeling Glossary

(This is work in progress)

Sculpted prims: A new prim type in Second Life. A sculpted prim is a prim whose shape is determined by a texture — its “sculpt texture”. Sculpted prims will allow for custom and more complex shapes to be brought into SL and used in building.

Sculpt Texture or “Sculpt Map”: Sculpt Textures are image files that contain the data for the shape of a sculpted prim. A sculpt texture is a standard RGB texture where the R, G, and B channels are mapped onto X, Y, and Z space. A sculpt texture is very similar to a “normal map”, but instead of encoding surface normals it encodes surface positions. See this wiki page for a detailed explanation.

Edge: An edge is any line drawn between two verticies and are one of the three sub-components of a polygon model that can be manipulated.

Face: Faces, also called polygons, are one of the three editable sub-components of a polygon model.

NURBS Modeling: NURBS is short for “Non Uniform Rational Bézier Spline”. This modeling method uses a series of curves and control points to define the model’s shape. If you have already worked with the Pen tool in Photoshop, Illustrator and similar programs, you’ve worked with Bezier curves in 2D. NURBS take the same concept into 3D. According to Qarl Linden, NURBS are the best thing to use for sculpt prims; it makes some sense since he worked most recently in movie special effects where NURBS are commonly used.

Polygon Mesh: The Polygon Meshis the most common modeling method used in 3D computer graphics (including Second Life). The process involves the direct manipulation of polygons (triangles and quadrilaterals), faces, vertices and edges to produce the desired shape.

Subdivision Surface: A methood of modeling that takes some of the best features of both NURBS and polygon meshes in which you manipulate a series of controll points on a model. The number of controll points can be increased (subdivided) or decreased at will, offering great flexability between fine and coarse controll.

Texture Maps: Texture Map is 3D graphics lingo for what most SL residents know as textures. The textures most SLers know and love are also known as “diffuse maps” or “color maps” within most programs; some people may also be familiar with “opacity maps”, “bump maps” and “normal maps”.

Unwrap: Unwraping is the process of manualy taking a 3d model, defining its seams and creating a flat template that defines how textures appear on that object. Clothing and skin designers are allready familiar with the SL avatar templates provided by Linden Lab and other Residents; those are the end-result of an unwrapping process.

UVW Mapping: The data in a model that defines the positioning of its textures, either automaticly, via an unwraping process or using a preset projection such as planar mapping, face mapping, box mapping, sphereical mapping, etc.

Vertex (plural: verticies); In a polygon mesh a vertex is a single point in 3d space and the smallest editable component of a model. Two verticies joined create an edge, three or more create a face.

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