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Tutorial 1: HelloWorld

This Tutorial shows how to set up the IDE for using the Irrlicht Engine and how to write a simple HelloWorld program with it. The program will show how to use the basics of the VideoDriver, the GUIEnvironment, and the SceneManager. Microsoft Visual Studio is used as an IDE, but you will also be able to understand everything if you are using a different one or even another operating system than windows.

You have to include the header file <irrlicht.h> in order to use the engine. The header file can be found in the Irrlicht Engine SDK directory `include`. To let the compiler find this header file, the directory where it is located has to be specified. This is different for every IDE and compiler you use. Let's explain shortly how to do this in Microsoft Visual Studio:

- If you use Version 6.0, select the Menu Extras -> Options. Select the directories tab, and select the 'Include' Item in the combo box. Add the `include` directory of the irrlicht engine folder to the list of directories. Now the compiler will find the Irrlicht.h header file. We also need the irrlicht.lib to be found, so stay in that dialog, select 'Libraries' in the combo box and add the `lib/VisualStudio` directory.
- If your IDE is Visual Studio .NET, select Tools -> Options. Select the projects entry and then select VC++ directories. Select 'show directories for include files' in the combo box, and add the `include` directory of the irrlicht engine folder to the list of directories. Now the compiler will find the Irrlicht.h header file. We also need the irrlicht.lib to be found, so stay in that dialog, select 'show directories for Library files' and add the `lib/VisualStudio` directory.

That's it. With your IDE set up like this, you will now be able to develop applications with the Irrlicht Engine.

Lets start!

After we have set up the IDE, the compiler will know where to find the Irrlicht Engine header files so we can include it now in our code.

#include <irrlicht.h>
irrlicht.h
Main header file of the irrlicht, the only file needed to include.

In the Irrlicht Engine, everything can be found in the namespace 'irr'. So if you want to use a class of the engine, you have to write irr:: before the name of the class. For example to use the IrrlichtDevice write: irr::IrrlichtDevice. To get rid of the irr:: in front of the name of every class, we tell the compiler that we use that namespace from now on, and we will not have to write irr:: anymore.

using namespace irr;
irr
Everything in the Irrlicht Engine can be found in this namespace.
Definition aabbox3d.h:13

There are 5 sub namespaces in the Irrlicht Engine. Take a look at them, you can read a detailed description of them in the documentation by clicking on the top menu item 'Namespace List' or by using this link: http://irrlicht.sourceforge.net/docu/namespaces.html Like the irr namespace, we do not want these 5 sub namespaces now, to keep this example simple. Hence, we tell the compiler again that we do not want always to write their names.

using namespace core;
using namespace scene;
using namespace video;
using namespace io;
using namespace gui;
irr::core
Basic classes such as vectors, planes, arrays, lists, and so on can be found in this namespace.
Definition aabbox3d.h:15
irr::gui
The gui namespace contains useful classes for easy creation of a graphical user interface.
Definition EGUIAlignment.h:11
irr::io
This namespace provides interfaces for input/output: Reading and writing files, accessing zip archive...
Definition EAttributes.h:11
irr::scene
All scene management can be found in this namespace: Mesh loading, special scene nodes like octrees a...
Definition CDynamicMeshBuffer.h:16
irr::video
The video namespace contains classes for accessing the video driver. All 2d and 3d rendering is done ...
Definition EDriverFeatures.h:11

To be able to use the Irrlicht.DLL file, we need to link with the Irrlicht.lib. We could set this option in the project settings, but to make it easy, we use a pragma comment lib for VisualStudio. On Windows platforms, we have to get rid of the console window, which pops up when starting a program with main(). This is done by the second pragma. We could also use the WinMain method, though losing platform independence then.

#ifdef _IRR_WINDOWS_
#pragma comment(lib, "Irrlicht.lib")
#pragma comment(linker, "/subsystem:windows /ENTRY:mainCRTStartup")
#endif

This is the main method. We can now use main() on every platform.

int main()
{

The most important function of the engine is the createDevice() function. The IrrlichtDevice is created by it, which is the root object for doing anything with the engine. createDevice() has 7 parameters:

- deviceType: Type of the device. This can currently be the Null-device, one of the two software renderers, D3D8, D3D9, or OpenGL. In this example we use EDT_SOFTWARE, but to try out, you might want to change it to EDT_BURNINGSVIDEO, EDT_NULL, EDT_DIRECT3D8, EDT_DIRECT3D9, or EDT_OPENGL.
- windowSize: Size of the Window or screen in FullScreenMode to be created. In this example we use 640x480.
- bits: Amount of color bits per pixel. This should be 16 or 32. The parameter is often ignored when running in windowed mode.
- fullscreen: Specifies if we want the device to run in fullscreen mode or not.
- stencilbuffer: Specifies if we want to use the stencil buffer (for drawing shadows).
- vsync: Specifies if we want to have vsync enabled, this is only useful in fullscreen mode.
- eventReceiver: An object to receive events. We do not want to use this parameter here, and set it to 0.

Always check the return value to cope with unsupported drivers, dimensions, etc.

IrrlichtDevice *device =
createDevice( video::EDT_SOFTWARE, dimension2d<u32>(640, 480), 16,
false, false, false, 0);
if (!device)
return 1;
irr::IrrlichtDevice
The Irrlicht device. You can create it with createDevice() or createDeviceEx().
Definition IrrlichtDevice.h:44
irr::video::EDT_SOFTWARE
@ EDT_SOFTWARE
The Irrlicht Engine Software renderer.
Definition EDriverTypes.h:26
irr::createDevice
IRRLICHT_API IrrlichtDevice *IRRCALLCONV createDevice(video::E_DRIVER_TYPE deviceType=video::EDT_SOFTWARE, const core::dimension2d< u32 > &windowSize=(core::dimension2d< u32 >(640, 480)), u32 bits=16, bool fullscreen=false, bool stencilbuffer=false, bool vsync=false, IEventReceiver *receiver=0)
Creates an Irrlicht device. The Irrlicht device is the root object for using the engine.

Set the caption of the window to some nice text. Note that there is an 'L' in front of the string. The Irrlicht Engine uses wide character strings when displaying text.

device->setWindowCaption(L"Hello World! - Irrlicht Engine Demo");
irr::IrrlichtDevice::setWindowCaption
virtual void setWindowCaption(const wchar_t *text)=0
Sets the caption of the window.

Get a pointer to the VideoDriver, the SceneManager and the graphical user interface environment, so that we do not always have to write device->getVideoDriver(), device->getSceneManager(), or device->getGUIEnvironment().

IVideoDriver* driver = device->getVideoDriver();
ISceneManager* smgr = device->getSceneManager();
IGUIEnvironment* guienv = device->getGUIEnvironment();
irr::IrrlichtDevice::getSceneManager
virtual scene::ISceneManager * getSceneManager()=0
Provides access to the scene manager.
irr::IrrlichtDevice::getVideoDriver
virtual video::IVideoDriver * getVideoDriver()=0
Provides access to the video driver for drawing 3d and 2d geometry.
irr::IrrlichtDevice::getGUIEnvironment
virtual gui::IGUIEnvironment * getGUIEnvironment()=0
Provides access to the 2d user interface environment.

We add a hello world label to the window, using the GUI environment. The text is placed at the position (10,10) as top left corner and (260,22) as lower right corner.

guienv->addStaticText(L"Hello World! This is the Irrlicht Software renderer!",
rect<s32>(10,10,260,22), true);

To show something interesting, we load a Quake 2 model and display it. We only have to get the Mesh from the Scene Manager with getMesh() and add a SceneNode to display the mesh with addAnimatedMeshSceneNode(). We check the return value of getMesh() to become aware of loading problems and other errors.

Instead of writing the filename sydney.md2, it would also be possible to load a Maya object file (.obj), a complete Quake3 map (.bsp) or any other supported file format. By the way, that cool Quake 2 model called sydney was modelled by Brian Collins.

IAnimatedMesh* mesh = smgr->getMesh("../../media/sydney.md2");
if (!mesh)
{
device->drop();
return 1;
}
IAnimatedMeshSceneNode* node = smgr->addAnimatedMeshSceneNode( mesh );
irr::IReferenceCounted::drop
bool drop() const
Drops the object. Decrements the reference counter by one.
Definition IReferenceCounted.h:116

To let the mesh look a little bit nicer, we change its material. We disable lighting because we do not have a dynamic light in here, and the mesh would be totally black otherwise. Then we set the frame loop, such that the predefined STAND animation is used. And last, we apply a texture to the mesh. Without it the mesh would be drawn using only a color.

if (node)
{
node->setMaterialFlag(EMF_LIGHTING, false);
node->setMD2Animation(scene::EMAT_STAND);
node->setMaterialTexture( 0, driver->getTexture("../../media/sydney.bmp") );
}
irr::scene::EMAT_STAND
@ EMAT_STAND
Definition IAnimatedMeshMD2.h:18

To look at the mesh, we place a camera into 3d space at the position (0, 30, -40). The camera looks from there to (0,5,0), which is approximately the place where our md2 model is.

smgr->addCameraSceneNode(0, vector3df(0,30,-40), vector3df(0,5,0));

Ok, now we have set up the scene, lets draw everything: We run the device in a while() loop, until the device does not want to run any more. This would be when the user closes the window or presses ALT+F4 (or whatever keycode closes a window).

while(device->run())
{
irr::IrrlichtDevice::run
virtual bool run()=0
Runs the device.

Anything can be drawn between a beginScene() and an endScene() call. The beginScene() call clears the screen with a color and the depth buffer, if desired. Then we let the Scene Manager and the GUI Environment draw their content. With the endScene() call everything is presented on the screen.

driver->beginScene(true, true, SColor(255,100,101,140));
smgr->drawAll();
guienv->drawAll();
driver->endScene();
}

After we are done with the render loop, we have to delete the Irrlicht Device created before with createDevice(). In the Irrlicht Engine, you have to delete all objects you created with a method or function which starts with 'create'. The object is simply deleted by calling ->drop(). See the documentation at irr::IReferenceCounted::drop() for more information.

device->drop();
return 0;
}

That's it. Compile and run.

- Irrlicht Engine Documentation © 2003-2012 by Nikolaus Gebhardt. Generated on for Irrlicht 3D Engine by Doxygen 1.15.0