Three lectures on the basic combat of X3D

In this lecture, we will describe how to create and construct a dot, a line, and its basic 2D graphics, and briefly introduce the X3d coordinate system.

Coordinates of a point and a point

You need to have clear coordinates for setting objects in a x3d scene. In the same scene, there is a unified coordinate system. This coordinate system is a right-handed coordinate system, at the beginning (that is, the observer does not move the position and change the view), the x-coordinate of the coordinate system is horizontally along the screen to the right, the y-axis is perpendicular to the screen, and the z-axis points to the user from the screen.

In the X3d, the coordinates of the points are (x, Y, z), the unit of the coordinates is the logical unit, that is, the X3d VRML unit, because it shows the graph is proportional, so you can take the unit as MM. The coordinate component values in the specified coordinates can be separated by spaces or separated by commas. The following example displays four points with the following code:

Description

(1) The node of the X3D support point is Pointset, which can contain color and coordinate nodes. The color node is the index table that is used to construct the color values to specify the colors of the corresponding points or objects, the coordinate node is the list used to construct the coordinates.

(2) in the Coordinate Node Properties window, click the Point property Content, pop-up a dialog box, add the coordinates of the following figure.