Hands On DarkBASIC Pro - Digital Skills

FIG-31.53
The SET GLOBAL
OBJECT CREATION
Statement
Summary
In the diagram:
SET
GLOBAL
mode 0 or 1. 0 - no vertex buffer sharing (this is the
default setting); 1 - vertex buffer sharing allowed.
Even if your own video card does allow vertex buffer sharing, your customer's may
not, so it's probably best to ignore this option.
� A point in 3D space is specified using x, y, and z coordinates.
� There are three main planes in 3D space - XY, YZ, and XZ.
� The computer screen uses a positive-up, negative-down y-axis when operating
in 3D mode. This is the opposite from the 2D settings.
� The positive z-axis travels away from the viewer "into" the screen.
� A point in space is known as a vertex.
� A set of vertices, when joined, form a polygon.
� The join between two vertices is known as an edge.
� Basic 3D shapes are known as primitives.
� When first created a 3D object has it centre position at the origin.
� The x and y axes intersect at the centre of the screen at start-up.
� Use the MAKE OBJECT CUBE to create a cube.
� Use MAKE OBJECT BOX to create a cuboid.
� Use MAKE OBJECT SPHERE to create a sphere.
� The number of polygons used can be specified when creating a sphere.
� Use MAKE OBJECT CYLINDER to create a cylinder.
� Use MAKE OBJECT CONE to create a cone.
� Use MAKE OBJECT PLAIN to create a plane.
� A plane is initially oriented as an XY plane.
OBJECT CREATION mode
� Use MAKE OBJECT TRIANGLE to create a triangle.
� The initial position of a triangle is determined by the vertices given.
� Use POSITION OBJECT to place the centre of an object at a new location.
786 DarkBASIC Pro: 3D Primitives