Horde3D Wiki - User contributions [en]

Tutorial - Setup Horde with SDL

2010-06-28T14:33:33Z

Pekuja: Fixed a few mistakes with the previous update.

{| border="0"
| {{ContentBlock|width=800|color=white
|content='''Here is a small example on how to use Horde with sdl.'''
Its a simple window that closes when the x is clicked
{{CppSourceCode|
description= Simple SDL Frame|
code=
<source lang="cpp" line="1">

#include <iostream>
#include <Horde3DUtils.h>
#include <SDL.h>

using namespace std;

H3DNode model = 0, cam = 0;

int main(int argc, char* args[]){
//Creates are bool value for the while loop.
bool running = true;

//Inits sdl with only the video extention.
if (SDL_Init(SDL_INIT_VIDEO) != 0) {
std::cerr << "SDL_Init failed: " << SDL_GetError() << std::endl;
return 0;
}

//Sets are window Caption
SDL_WM_SetCaption("Simple SDL Frame",NULL);

//Sets the sdl video mode width and height as well has creates are opengl context.
if (!SDL_SetVideoMode(800,600,32,SDL_OPENGL)) {
std::cerr << "SDL_SetVideoMode failed: " << SDL_GetError() << std::endl;
return 0;
}

//Creates Our Event Reciver
SDL_Event event;

//Inits Horde3D
h3dInit();

//Sizes the Horde3D View
h3dSetupViewport( 0, 0, 800, 600, true );

// Add pipeline resource
H3DRes pipeRes = h3dAddResource( H3DResTypes::Pipeline, "standard.pipeline.xml", 0 );
// Add model resource
H3DRes modelRes = h3dAddResource( H3DResTypes::SceneGraph, "character.scene.xml", 0 );
// Add animation resource
H3DRes animRes = h3dAddResource( H3DResTypes::Animation, "walk.anim.xml", 0 );
// Load added resources
h3dutLoadResourcesFromDisk( "" );

// Add model to scene
model = h3dAddNodes( H3DRootNode, modelRes );
// Apply animation
h3dSetupModelAnimStage( model, 0, animRes, 0, "", false );

// Add light source
H3DNode light = h3dAddLightNode( H3DRootNode, "Light1", 0, "LIGHTING", "SHADOWMAP" );
// Set light position and radius
h3dSetNodeTransform( light, 0, 20, 0, 0, 0, 0, 1, 1, 1 );

//Sets the lightnodes radius
h3dSetNodeParamF( light, H3DLight::RadiusF, 0, 50 );
//Sets the lightnodes Field of view
h3dSetNodeParamF( light, H3DLight::FovF, 0, 90 );
//Sets the lightnodes ShadowMapCOunt
h3dSetNodeParamI( light, H3DLight::ShadowMapCountI, 3 );
//Sets the lightnodes ShadowSplitLambda
h3dSetNodeParamF( light, H3DLight::ShadowSplitLambdaF, 0, 0.9f );
//Sets the lightnodes ShadowMapBias
h3dSetNodeParamF( light, H3DLight::ShadowMapBiasF, 0, 0.001f );
//Sets the lightnodes red value
h3dSetNodeParamF( light, H3DLight::ColorF3, 0, 0.9f );
//Sets the lightnodes green value
h3dSetNodeParamF( light, H3DLight::ColorF3, 1, 0.7f );
//Sets the lightnodes blue value
h3dSetNodeParamF( light, H3DLight::ColorF3, 2, 0.75f );

// Add camera
cam = h3dAddCameraNode( H3DRootNode, "Camera", pipeRes );

// Our While loop
while(running == true){
static float t = 0;

// Increase animation time
t = t + 10.0f * (1 / 60);
//Checks if there is a event that needs processing
if(SDL_PollEvent(&event)){
//Checks to see if the event is a SDL_QUIT*x on the window is clicked*
if(event.type == SDL_QUIT){
//Sets the while loop to false and ends program
running = false;
}
}

// Play animation
h3dSetModelAnimParams( model, 0, t, 1.0f );

// Set new model position
h3dSetNodeTransform( model, t * 10, 0, 0, // Translation
0, 0, 0, // Rotation
1, 1, 1 ); // Scale
// Render scene
h3dRender( cam );

//Swaps the sdl opengl buffers
SDL_GL_SwapBuffers();
}
//Releases the Horde3D Engine
h3dRelease();
//Releases SDL and quits the program
SDL_Quit();

}
</source>
}}
--[[User:Wild13|Rj]] 05:28, 1 August 2008 (CEST)
}}
| valign="top" | {{Extension_Summary|
name = Horde With SDL|
screenshot = H3DPlaceHolder.png|
description = This tutorial introduces the use of Horde3D with SDL|
version = 1.0|
horde3dversion = 1.0 beta|
released = 2008-07-31|
author = Raynaldo Rivera|
}}
|}
[[category: Tutorials]]

Tutorial - Setup Horde with SDL

2010-06-28T14:27:54Z

Pekuja: Updated the code to work with Beta4 and SVN trunk.

{| border="0"
| {{ContentBlock|width=800|color=white
|content='''Here is a small example on how to use Horde with sdl.'''
Its a simple window that closes when the x is clicked
{{CppSourceCode|
description= Simple SDL Frame|
code=
<source lang="cpp" line="1">

#include <iostream>
#include <Horde3DUtils.h>
#include <SDL.h>

using namespace std;

H3DNode model = 0, cam = 0;

int main(int argc, char* args[]){
//Creates are bool value for the while loop.
bool running = true;

//Inits sdl with only the video extention.
if (SDL_Init(SDL_INIT_VIDEO) != 0) {
std::cerr << "SDL_Init failed: " << SDL_GetError() << std::endl;
return 0;
}

//Sets are window Caption
SDL_WM_SetCaption("Simple SDL Frame",NULL);

//Sets the sdl video mode width and height as well has creates are opengl context.
if (!SDL_SetVideoMode(800,600,32,SDL_OPENGL)) {
std::cerr << "SDL_SetVideoMode failed: " << SDL_GetError() << std::endl;
return 0;
}

//Creates Our Event Reciver
SDL_Event event;

//Inits Horde3D
h3dInit();

//Sizes the Horde3D View
h3dResize( 0, 0, 800, 600 );

// Add pipeline resource
H3DRes pipeRes = h3dAddResource( H3DResTypes::Pipeline, "standard.pipeline.xml", 0 );
// Add model resource
H3DRes modelRes = h3dAddResource( H3DResTypes::SceneGraph, "character.scene.xml", 0 );
// Add animation resource
H3DRes animRes = h3dAddResource( H3DResTypes::Animation, "walk.anim.xml", 0 );
// Load added resources
h3dutLoadResourcesFromDisk( "" );

// Add model to scene
model = h3dAddNodes( H3DRootNode, modelRes );
// Apply animation
h3dSetupModelAnimStage( model, 0, animRes, "", false );

// Add light source
H3DNode light = h3dAddLightNode( H3DRootNode, "Light1", 0, "LIGHTING", "SHADOWMAP" );
// Set light position and radius
h3dSetNodeTransform( light, 0, 20, 0, 0, 0, 0, 1, 1, 1 );

//Sets the lightnodes radius
h3dSetNodeParamf( light, H3DLight::RadiusF, 0, 50 );
//Sets the lightnodes Field of view
h3dSetNodeParamf( light, H3DLight::FovF, 0, 90 );
//Sets the lightnodes ShadowMapCOunt
h3dSetNodeParami( light, H3DLight::ShadowMapCountI, 0, 3 );
//Sets the lightnodes ShadowSplitLambda
h3dSetNodeParamf( light, H3DLight::ShadowSplitLambdaF, 0, 0.9f );
//Sets the lightnodes ShadowMapBias
h3dSetNodeParamf( light, H3DLight::ShadowMapBiasF, 0, 0.001f );
//Sets the lightnodes red value
h3dSetNodeParamf( light, H3DLight::ColorF3, 0, 0.9f );
//Sets the lightnodes green value
h3dSetNodeParamf( light, H3DLight::ColorF3, 1, 0.7f );
//Sets the lightnodes blue value
h3dSetNodeParamf( light, H3DLight::ColorF3, 2, 0.75f );

// Add camera
cam = h3dAddCameraNode( RootNode, "Camera", pipeRes );

// Our While loop
while(running == true){
static float t = 0;

// Increase animation time
t = t + 10.0f * (1 / 60);
//Checks if there is a event that needs processing
if(SDL_PollEvent(&event)){
//Checks to see if the event is a SDL_QUIT*x on the window is clicked*
if(event.type == SDL_QUIT){
//Sets the while loop to false and ends program
running = false;
}
}

// Play animation
h3dSetModelAnimParams( model, 0, t, 1.0f );

// Set new model position
h3dSetNodeTransform( model, t * 10, 0, 0, // Translation
0, 0, 0, // Rotation
1, 1, 1 ); // Scale
// Render scene
h3dRender( cam );

//Swaps the sdl opengl buffers
SDL_GL_SwapBuffers();
}
//Releases the Horde3D Engine
h3dRelease();
//Releases SDL and quits the program
SDL_Quit();

}
</source>
}}
--[[User:Wild13|Rj]] 05:28, 1 August 2008 (CEST)
}}
| valign="top" | {{Extension_Summary|
name = Horde With SDL|
screenshot = H3DPlaceHolder.png|
description = This tutorial introduces the use of Horde3D with SDL|
version = 1.0|
horde3dversion = 1.0 beta|
released = 2008-07-31|
author = Raynaldo Rivera|
}}
|}
[[category: Tutorials]]

Tutorial - Simple HUD

2010-06-28T14:21:19Z

Pekuja: Updated the references to function names in the tutorial text.

__NOTOC__ __NOEDITSECTION__{{ContentBlock|color=white|content={{!!}}
AS OF January 9th, 2009 THIS ARTICLE IS A WORK IN PROGRESS.

=Tutorial Objectives=
* Explanation of overlay procedures and layout format
* Create basic utility classes for working with overlays
** Vec2f
** BasicRect
* Create a simple HUD Manager
* Create a root HUDObject class, from which the following derive
** HUDPanel
** HUDGauge
** HUDLabel

==Tutorial Notation==
Information of that is purely of technical or artistic concern will be presented in subsections addressed to the relevant party. Feel free to skip those that do not pertain to you.

=Part I: Horde3D Overlays=
Overlays are special objects which are drawn ontop of a rendered scene. Quoting the Horde3D API reference on the function "h3dShowOverlay()":
<blockquote>An overlay is a 2D image that can be used to render 2D GUI elements. [...] Overlays can have different layers which describe the order in which they are drawn. Overlays with smaller layer numbers are drawn before overlays with higher layer numbers.</blockquote>

The function used to display an overlay is: ''void h3dShowOverlay( float x_ll, float y_ll, float u_ll, float v_ll, float x_lr, float y_lr, float u_lr, float v_lr, float x_ur, float y_ur, float u_ur, float v_ur, float x_ul, float y_ul, float u_ul, float v_ul, int layer, H3DRes materialRes )'' That's a pretty monstrous function, which is why we're going to create some basic structures to do the hard work.

[INSERT SCREEN COORDINATE SYSTEM PICTURE HERE]

<B>IMPORTANT INFORMATION.</B> Horde3D begins its screen space coordinate system at the bottom left corner. Hence the bottom left corner is coordinate (0,0), the bottom right is (1,0), the top left is (0,1), and the top right is (1,1). ALWAYS REMEMBER THIS.

=Utility Classes=
<Source lang=cpp>
//2-Dimensional point struct, later we'll add interpolation
struct Vec2f
{
float x, y;
Vec2f(float vx, float vy)
{
set(vx,vy);
};
void set(float vx, float vy)
{
x = vx; y = vy;
};
Vec2f()
{
x = y = 0;
};
};

//Basic Rectangle structure, later it'll receive a clipping function
struct basicRect
{
Vec2f upperLeft, upperRight, lowerLeft, lowerRight;
basicRect(){};
basicRect(Vec2f ul, Vec2f ur, Vec2f ll, Vec2f lr)
{
upperLeft = ul;
upperRight = ur;
lowerLeft = ll;
lowerRight = lr;
};
basicRect(Vec2f ll, Vec2f ur)
{
setSimpleExtents(ll,ur);
};
void setSimpleExtents(Vec2f ll, Vec2f ur)
{
upperLeft.set(ll.x, ur.y);
upperRight = ur;
lowerLeft = ll;
lowerRight.set(ur.x, ll.y);
};
void moveX(float val)
{
upperLeft.x += val;
lowerLeft.x += val;
upperRight.x += val;
upperLeft.x += val;
};
void moveY(float val)
{
upperLeft.y += val;
lowerLeft.y += val;
upperRight.y += val;
upperLeft.y += val;
};
void move(float x, float y)
{
moveX(x); moveY(y);
};
void flipHorizontal()
{
Vec2f tX, tY;
tX = upperLeft;
tY = lowerLeft;
upperLeft = upperRight;
lowerLeft = lowerRight;
upperRight = tX;
lowerRight = tY;
};
void flipVertical()
{
Vec2f tX, tY;
tX = upperLeft;
tY = upperRight;
upperLeft = lowerLeft;
upperRight = lowerRight;
lowerLeft = tX;
lowerRight = tY;
};
void setEdges(float top, float right, float bottom, float left)
{
setTop(top);
setBottom(bottom);
setRight(right);
setLeft(left);
};
void setTop(float val)
{
upperLeft.y = val;
upperRight.y = val;
};
void setBottom(float val)
{
lowerLeft.y = val;
lowerRight.y = val;
};
void setLeft(float val)
{
upperLeft.x = val;
lowerLeft.x = val;
};
void setRight(float val)
{
upperRight.x = val;
lowerRight.x = val;
};
};
</Source>
}}

Tutorial - Picking

2010-06-28T14:19:19Z

Pekuja: Updated the code to work with Beta4 and SVN trunk.

{| border="0"
| {{ContentBlock|width=800|color=white
|content={{!!}}
== Picking the mesh under the mouse cursor ==

Picking an object within the scene is a common problem.
Supposing you want to select the object using a mouse the following sample will show you how you get the NodeHandle for the object under the mouse cursor.

Based on the '''knight example''' in the Horde3D SDK we will first remove the mouseMoveListener. To enable the mouse cursor again we have to remove the <br />
''glfwDisable( GLFW_MOUSE_CURSOR );'' and ''glfwEnable( GLFW_MOUSE_CURSOR );'' statements, too.

Then we define a mouseButtonListener in the '''main.cpp''':

{{CppSourceCode|
description= Normalize mouse button for Horde3DUtils::pickNode.|
code=
<source lang="cpp" line="1">
void GLFWCALL mouseButtonListener( int button, int action )
{
// If left mouse button has been pressed...
if( button == GLFW_MOUSE_BUTTON_LEFT && action == GLFW_PRESS)
{
int x, y;
int width, height;
// get mouse position
glfwGetMousePos(&x, &y);
// get window size for normalization
glfwGetWindowSize(&width, &height);
// pick the node under the normalized mouse position
app->pick( x / float( width ), (height - y) / float( height ) );
}
}
</source>
}}
To activate that listener we have to add the following code to the '''setupWindow''' method:

{{CppSourceCode|description=Activate mouse button listener|code=<source lang="cpp" line="1">
glfwSetMouseButtonCallback( mouseButtonListener );
</source>
}}

For the use of [http://www.horde3d.org/docs/_utils.html#pickNode Horde3DUtils::pickNode] we have to normalize the window coordinates received by ''glfwGetMousePos''. That's why we need to call ''glfwGetWindowSize'' additionally. Another conversion has to be made, since GLFW has it's origin in the upper left corner while Horde3D requires the origin to be in the lower left corner.

Then in the '''app.cpp''' we implement a call to the h3dutPickNode utility function.

{{CppSourceCode|
description= Get the NodeHandle under the mouse cursor.|
code=
<source lang="cpp" line="1">
void Application::pick( float dX, float dY )
{
H3DNode node = h3dutPickNode(_cam, dX, dY);
}
</source>
}}
}}
| valign="top" | {{Extension_Summary|
name = Picking Tutorial|
screenshot = H3DPlaceHolder.png|
description = This tutorial present how to pick an object in a 3D scene.|
version = 1.0|
horde3dversion = 1.0 beta|
released = 2008-04-15|
author = Volker Wiendl|
}}
|}
[[category: Tutorials]]

Tutorial - Hello World

2010-06-28T14:14:45Z

Pekuja: Updated the references to function names in the tutorial text.

{| border="0"
| {{ContentBlock|width=800|color=white
|content='''In this section we will create a simple application that loads a character and animates it using a walk cycle. You will see how straightforward it is to use the Horde3D API.'''

As a first step you have to create an application that opens a window which can be used for rendering. This is a pretty standard task and if you are a novice and have problems with that on your platform use Google to find one of the numerous good tutorials on the net or have a look at the samples that come with the Horde3D SDK. The next step is to initialize an OpenGL context for our rendering window. You can do this manually or use the Horde3D Utility Library to make your life easier. After that is done we can finally get to the engine related part.

{{CppSourceCode|
description= Simple Setup of the Horde3D renderer.|
code=
<source lang="cpp" line="1">
#include <Horde3D.h>
#include <Horde3DUtils.h>

H3DNode model = 0, cam = 0;

void initGame( int winWidth, int winHeight )
{
// Initialize engine
h3dInit();
h3dSetupViewport( 0, 0, winWidth, winHeight, true );

// Add pipeline resource
H3DRes pipeRes = h3dAddResource( H3DResTypes::Pipeline, "standard.pipeline.xml", 0 );
// Add model resource
H3DRes modelRes = h3dAddResource( H3DResTypes::SceneGraph, "character.scene.xml", 0 );
// Add animation resource
H3DRes animRes = h3dAddResource( H3DResTypes::Animation, "walk.anim.xml", 0 );
// Load added resources
h3dutLoadResourcesFromDisk( "" );

// Add model to scene
model = h3dAddNodes( H3DRootNode, modelRes );
// Apply animation
h3dSetupModelAnimStage( model, 0, animRes, 0, "", false );

// Add light source
H3DNode light = h3dAddLightNode( H3DRootNode, "Light1", 0, "LIGHTING", "SHADOWMAP" );
// Set light position and radius
h3dSetNodeTransform( light, 0, 20, 0, 0, 0, 0, 1, 1, 1 );
h3dSetNodeParamF( light, H3DLight::RadiusF, 0, 50.0f );

// Add camera
H3DNode cam = h3dAddCameraNode( H3DRootNode, "Camera", pipeRes );
}
</source>
}}

The first line of the code above declares two global handles to Horde scene graph nodes. All objects in Horde are accessible via handles, a concept similar to pointers. The first thing we need to do in our initGame function to use Horde3D is initializing the engine. This happens with the function h3dInit. After that we tell the engine the size of our rendering window so that it can adjust the viewport.

The next step is to load the required resources. In Horde resources are data files that are loaded once and can be referenced by several objects for rendering. The function h3dAddResource takes the resource type we want to add and the name of the resource (usually the filename) as parameters and returns a handle to the created resource object. In our case we want a model which is represented as a scene graph file in Horde and additionally an animation. Now the resources are created but we still need to load them. Horde supports loading from any sources including encrypted archives or a network but in this case we just want to load our resources from the local hard disk which is done with the utility function h3dutLoadResourcesFromDisk. Besides our model and animation we also load a pipeline resource. A pipeline defines how the the scene is rendered and can be used to realize post-processing effects or high dynamic range rendering. For the beginning you can just use the files that come with the SDK samples.

After we have loaded the required resources we can finally build up the scene graph. The scene graph represents the objects in our virtual world in a hierarchical tree structure. First we add the model that we have loaded before. We use the function h3dAddNodes for doing this which takes a scene graph resource and a parent node. The parent is the scene object to which the new node is attached, in our case just the root node which is the base of the virtual world. Similar to h3dAddResource this function also returns a handle to the created scene graph subtree. After that we assign the loaded animation to our model node with the function h3dSetupModelAnimStage. Horde allows you to apply several different animations to a model and makes it possible to blend and mix them but for the beginning one should be enough. Now that adding the model is finished we still need a light source. It would be possible to load another scene graph file which contains the light source but we want to add it manually by using the h3dAddLightNode function. This function requires several parameters specifying the shaders used for rendering. More information on this can be found in other sections of the manual. The next step is to set the position and orientation which is done with h3dSetNodeTransform. After that we specify the light radius which defines the zone of influence using h3dSetNodeParamF. Finally we still need a camera which represents the viewer. It is added with the function h3dAddCameraNode and takes our loaded pipeline resource as parameter.

{{CppSourceCode|
description= Game Loop and Destructor|
code=
<source lang="cpp" line="1">
void gameLoop( float fps )
{
static float t = 0;

// Increase animation time
t = t + 10.0f * (1 / fps);

// Play animation
h3dSetModelAnimParams( model, 0, t, 1.0f );

// Set new model position
h3dSetNodeTransform( model, t * 10, 0, 0, // Translation
0, 0, 0, // Rotation
1, 1, 1 ); // Scale

// Render scene
h3dRender( cam );

// Finish rendering of frame
h3dFinalizeFrame();
}

void releaseGame()
{
// Release engine
h3dRelease();
}
</source>
}}

The next function in our sample is the game loop which is called once every frame. Here we will animate our character model. For doing this we define a time counter which is increased in every frame. To make the animation speed independent from the framerate, we scale the time step by the inverse of the current frames per second value. After that we tell the engine to update the model animation using the h3dSetModelAnimParams function. We could also specify a blend weight for combining animations here but since we have only one animation we don't need that. Now we can displace our character a bit so that it moves through the scene. This is achieved by updating the model node transformation. Finally we need to tell the engine to render the scene and recalculate the model animation. This happens with the function h3dRender that expects the camera from which the scene is viewed.

The last function releaseGame is called when the application is closed. All we have to do here is freeing the engine with the h3dRelease function.

That's it so far with the basic tutorial. You can have a look at the Usage Guide now to learn more details.
}}
| valign="top" | {{Extension_Summary|
name = Hello World Tutorial|
screenshot = H3DPlaceHolder.png|
description = This tutorial introduces the basic steps necessary to setup horde3d|
version = 1.0|
horde3dversion = 1.0 beta|
released = 2008-03-30|
author = Nicolas Schulz|
}}
|}
[[category: Tutorials]]

Tutorial - Hello World

2010-06-28T14:11:29Z

Pekuja: Updated the code to work with Beta4 and SVN trunk.

{| border="0"
| {{ContentBlock|width=800|color=white
|content='''In this section we will create a simple application that loads a character and animates it using a walk cycle. You will see how straightforward it is to use the Horde3D API.'''

As a first step you have to create an application that opens a window which can be used for rendering. This is a pretty standard task and if you are a novice and have problems with that on your platform use Google to find one of the numerous good tutorials on the net or have a look at the samples that come with the Horde3D SDK. The next step is to initialize an OpenGL context for our rendering window. You can do this manually or use the Horde3D Utility Library to make your life easier. After that is done we can finally get to the engine related part.

{{CppSourceCode|
description= Simple Setup of the Horde3D renderer.|
code=
<source lang="cpp" line="1">
#include <Horde3D.h>
#include <Horde3DUtils.h>

H3DNode model = 0, cam = 0;

void initGame( int winWidth, int winHeight )
{
// Initialize engine
h3dInit();
h3dSetupViewport( 0, 0, winWidth, winHeight, true );

// Add pipeline resource
H3DRes pipeRes = h3dAddResource( H3DResTypes::Pipeline, "standard.pipeline.xml", 0 );
// Add model resource
H3DRes modelRes = h3dAddResource( H3DResTypes::SceneGraph, "character.scene.xml", 0 );
// Add animation resource
H3DRes animRes = h3dAddResource( H3DResTypes::Animation, "walk.anim.xml", 0 );
// Load added resources
h3dutLoadResourcesFromDisk( "" );

// Add model to scene
model = h3dAddNodes( H3DRootNode, modelRes );
// Apply animation
h3dSetupModelAnimStage( model, 0, animRes, 0, "", false );

// Add light source
H3DNode light = h3dAddLightNode( H3DRootNode, "Light1", 0, "LIGHTING", "SHADOWMAP" );
// Set light position and radius
h3dSetNodeTransform( light, 0, 20, 0, 0, 0, 0, 1, 1, 1 );
h3dSetNodeParamF( light, H3DLight::RadiusF, 0, 50.0f );

// Add camera
H3DNode cam = h3dAddCameraNode( H3DRootNode, "Camera", pipeRes );
}
</source>
}}

The first line of the code above declares two global handles to Horde scene graph nodes. All objects in Horde are accessible via handles, a concept similar to pointers. The first thing we need to do in our initGame function to use Horde3D is initializing the engine. This happens with the function init. After that we tell the engine the size of our rendering window so that it can adjust the viewport.

The next step is to load the required resources. In Horde resources are data files that are loaded once and can be referenced by several objects for rendering. The function addResource takes the resource type we want to add and the name of the resource (usually the filename) as parameters and returns a handle to the created resource object. In our case we want a model which is represented as a scene graph file in Horde and additionally an animation. Now the resources are created but we still need to load them. Horde supports loading from any sources including encrypted archives or a network but in this case we just want to load our resources from the local hard disk which is done with the utility function loadResourcesFromDisk. Besides our model and animation we also load a pipeline resource. A pipeline defines how the the scene is rendered and can be used to realize post-processing effects or high dynamic range rendering. For the beginning you can just use the files that come with the SDK samples.

After we have loaded the required resources we can finally build up the scene graph. The scene graph represents the objects in our virtual world in a hierarchical tree structure. First we add the model that we have loaded before. We use the function addNodes for doing this which takes a scene graph resource and a parent node. The parent is the scene object to which the new node is attached, in our case just the root node which is the base of the virtual world. Similar to addResource this function also returns a handle to the created scene graph subtree. After that we assign the loaded animation to our model node with the function setupModelAnimStage. Horde allows you to apply several different animations to a model and makes it possible to blend and mix them but for the beginning one should be enough. Now that adding the model is finished we still need a light source. It would be possible to load another scene graph file which contains the light source but we want to add it manually by using the addLightNode function. This function requires several parameters specifying the shaders used for rendering. More information on this can be found in other sections of the manual. The next step is to set the position and orientation which is done with setNodeTransform. After that we specify the light radius which defines the zone of influence using setLightParam. Finally we still need a camera which represents the viewer. It is added with the function addCameraNode and takes our loaded pipeline resource as parameter.

{{CppSourceCode|
description= Game Loop and Destructor|
code=
<source lang="cpp" line="1">
void gameLoop( float fps )
{
static float t = 0;

// Increase animation time
t = t + 10.0f * (1 / fps);

// Play animation
h3dSetModelAnimParams( model, 0, t, 1.0f );

// Set new model position
h3dSetNodeTransform( model, t * 10, 0, 0, // Translation
0, 0, 0, // Rotation
1, 1, 1 ); // Scale

// Render scene
h3dRender( cam );

// Finish rendering of frame
h3dFinalizeFrame();
}

void releaseGame()
{
// Release engine
h3dRelease();
}
</source>
}}

The next function in our sample is the game loop which is called once every frame. Here we will animate our character model. For doing this we define a time counter which is increased in every frame. To make the animation speed independent from the framerate, we scale the time step by the inverse of the current frames per second value. After that we tell the engine to update the model animation using the setModelAnimParams function. We could also specify a blend weight for combining animations here but since we have only one animation we don't need that. Now we can displace our character a bit so that it moves through the scene. This is achieved by updating the model node transformation. Finally we need to tell the engine to render the scene and recalculate the model animation. This happens with the function render that expects the camera from which the scene is viewed.

The last function releaseGame is called when the application is closed. All we have to do here is freeing the engine with the release function.

That's it so far with the basic tutorial. You can have a look at the Usage Guide now to learn more details.
}}
| valign="top" | {{Extension_Summary|
name = Hello World Tutorial|
screenshot = H3DPlaceHolder.png|
description = This tutorial introduces the basic steps necessary to setup horde3d|
version = 1.0|
horde3dversion = 1.0 beta|
released = 2008-03-30|
author = Nicolas Schulz|
}}
|}
[[category: Tutorials]]