S60 3rd Edition SDK for Symbian OS
Example Applications Guide |
OpenGL ES Billboard Example
1. About this Example
2. Prerequisites
3. Design and Implementation
This example demonstrates the billboarding technique. Billboarding is a way of making 2D sprites look 3D. It is achieved by applying a 2D texture bitmap to a rectangular primitive. The primitive is then rotated so that it always faces the camera. This technique is often used in games to render trees, bushes, clouds, fire, smoke, explosions, and so on.
This example can be extended to any kind of OpenGL ES application, but you might want to look at the other example applications as well for how to use other, different kinds of, OpenGL ES features.
Only classes used by this example are the basic UI framework baseclasses. Open GL ES itself is pure C method call API and doesn't use classes.
To build and run this example you need to have the S60 SDK installed and working correctly on your computer. You also need basic understanding on how to build S60 applications.
To work with this example application you need basic understanding on how to build S60 applications and basic undestanding of how Symbian (or COE) UI and application framework works. Also basic knowledge on OpenGL or OpenGL ES is required if you wish to modify the example.
By using billboarding, 3D applications can sometimes gain speed, as the billboard is much faster to draw than a detailed model of a tree, for example. This example uses the T3DModel::MakeBillboardWorldViewMatrix(…) in order to achieve the effect. As in this example, Billboarding can be combined with color keying to render objects that have non-rectangular images.
The application has capability NONE as it only needs the rights to execute and access to the screen.
All Open GL ES examples support various screen modes. The examples also support changing the screen size while the application is running. Note that this support must be coded in the application and this code resides in the container's SizeChanged() method.
This inheritance list is sorted roughly, but not completely, alphabetically:
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