JMP 14.0 Online Documentation (English)
Discovering JMP
Using JMP
Basic Analysis
Essential Graphing
Profilers
Design of Experiments Guide
Fitting Linear Models
Predictive and Specialized Modeling
Multivariate Methods
Quality and Process Methods
Reliability and Survival Methods
Consumer Research
Scripting Guide
JSL Syntax Reference
JMP iPad Help
JMP Interactive HTML
Capabilities Index
JMP 13 Online Documentation
JMP 12 Online Documentation
Scripting Guide
•
Three-Dimensional Scenes
•
Lighting and Normals
• Normal Vectors
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Normal Vectors
Normal vectors point in a direction perpendicular to a surface. For a plane, all normals are the same. For a more complicated surface, normals are more complicated. JSL enables you to specify the normal vector for each vertex. These normals specify the orientation of the surface in space, necessary for lighting calculations. Accurate normals assure accurate lighting.
The normal vector is of length 1 and is perpendicular to the vertex. Typically, a vertex is shared between several polygons and a smooth shaded effect is desired, so the perpendicular at the vertex is calculated as a (possibly weighted) average of the polygon’s normals. It is important to calculate the “outward” normal for polygons unless two-sided shading is enabled because only the outer face of the polygon is illuminated. With a scaled polygon, the normal’s length is not 1 after scaling, and the lighting is wrong.
Normal vectors are set at the same time the surface is constructed, and are specified with the
Normal
command. Use the
Enable(NORMALIZE)
command to have the normals re-normalized to 1 each time the scene is drawn.
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Help created on 7/12/2018