Scaling 3D Objects

This section covers how to scale (enlarge or shrink) models and polygons.

Scaling a Model

To scale a model, use the scaleModel(...) function.

- Function Format -

Arguments:

• modelID: Specifies the ID of the model to be scaled.
• sx, sy, sz: Specify the scale factors for the X, Y, and Z directions respectively. A value greater than 1.0 enlarges the model, while a value less than 1.0 shrinks it. To keep the original size in a direction, use 1.0.

Scaling a Polygon

To scale a polygon, use the scalePolygon(...) function.

- Function Format -

Arguments:

• polygonID: Specifies the ID of the polygon to be scaled.
• sx, sy, sz: Specify the scale factors for the X, Y, and Z directions respectively. A value greater than 1.0 enlarges the polygon, while a value less than 1.0 shrinks it. To keep the original size in a direction, use 1.0.

Example Program

Let's place a sphere model and stretch it by a factor of 2 along the Z-axis. Write and run the following code:

import graphics3d.Graphics3DFramework;
import Graphics3D;

// Function called at the start of the program
void onStart ( int rendererID ) {

	// Optional: Set window size and background color
	setWindowSize( 800, 600 );
	setBackgroundColor( 0, 0, 0, 255 );


	// Create and place an axis model
	int axis = newAxisModel( 3.0, 3.0, 3.0 );
	mountModel( axis, rendererID );

	// Create and place a sphere model
	int sphere = newSphereModel( 1.0, 1.0, 1.0, 10, 7 );
	mountModel( sphere, rendererID );

	// Stretch the sphere 2x in the Z direction
	scaleModel( sphere, 1.0, 1.0, 2.0 );
}

When you run this program, a white sphere will appear on a black background. The sphere is stretched 2x in the Z direction.

Execution Result

The sphere model appears scaled along the Z-axis.