Graphics

IGE graphics features help to create beautiful, optimized graphics across a range of platforms, from mobile to desktop through an easy to use workflow.

Assets workflow

Graphics assets including model, animation, texture and shader can be loaded, converted and displayed using IGE.

Animation and model files such as Collada DAE and FBX are imported to IGE then converted to IGE optimized format in which:

*.pyxf: Use for model
*.pyxa: Use for animation

Texture files are imported and converted to:

*.pyxi: Use for texture

Render Pipeline

The builtin render pipeline is implemented using forward rendering technique, which utilize OpenGL 3.x / OpenGLES 3.x API.

Forward rendering renders each object in one or more passes:

OpaquePass

TransparentPass

ShadowPass

Camera

A game represents game objects in a 3D space. The device’s screen is 2D space, thus using camera help to capture the scene to display it in the device screen.

Camera can be created by adding a Camera component to a game object, or using Create Menu -> Camera.

Using perspective camera, objects which are far away are smaller than those nearby which is similar to the real life. Orthographic camera is useful to display the scene where all objects appear at the same scale, like GUI or isometric view.

Camera inspector reference:

Property	Function
FOV	Field of view
Near	Near clipping
Far	Far clipping
Aspect	Aspect ratio
Up	Up vector: 0 = X, 1 = Y, 2 = Z
Ortho	Orthographic or perspective camera
OrtW	Ortho width
OrtH	Ortho height
LockTarget	Lock target, create follow camera
Target	Position of target to follow
wBase	Whether width based or heigh based scaled
ScrScale	Screen scale factor
ScrOffset	Screen offset factor
ScrRot	Screen rotation factor
ClearColor	Color set to when clear screen

Camera can be controlled by using Python API, with module igeScene.Camera. Check the Camera API Document for more info.

Multiple camera also supported, but only one active camera can be used at a time (in combination with builtin GUI Camera). To set current camera as active, use Python API as example below:

from igeScene import Script

class GameManager(Script):
    def __init__(self, owner):
        super().__init__(owner)

    def onUpdate(self, dt):
        # find a camera and set it active
        camera = self.owner.scene.findObjectByName("MyCamera")
        if camera is not None:
            self.owner.scene.activeCamera = camera

Lighting

Ambient Light

Ambient light is diffuse environmental light that is present all around the Scene and doesn’t come from any specific source object. It can be an important contributor to the overall look and brightness of a scene.

Ambient light can be useful in a number of cases, depending upon your chosen art style. An example would be bright, cartoon-style rendering where dark shadows may be undesirable or where lighting is perhaps hand-painted into textures. It can also be useful if you need to increase the overall brightness of a scene without adjusting individual lights.

Property	Function
SkyColor	Ambient sky color
GroundColor	Ambient ground color
Direction	Ambient direction vector

Tip

AmbientLight component is usually attached to the root node of the object hierarchy tree, because one scene needs only one Ambient light settings.

Point Light

A Point Light is located at a point in space and sends light out in all directions equally. The direction of light hitting a surface is the line from the point of contact back to the center of the light object.

Property	Function
Color	Light color
Intensity	Light intensity value
Range	Range of effectiveness

Spot Light

Like a Point Light, a Spot Light has a specified location and range over which the light falls off. However, a Spot Light is constrained to an angle, resulting in a cone-shaped region of illumination.

Property	Function
Color	Light color
Intensity	Light intensity value
Range	Range of effectiveness
Angle	Constrained angle

Directional Light

Directional Lights are useful for creating effects such as sunlight in your scenes. Behaving in many ways like the sun, directional lights can be thought of as distant light sources which exist infinitely far away. A Directional Light doesn’t have any identifiable source position and so the light object can be placed anywhere in the scene. All objects in the scene are illuminated as if the light is always from the same direction.

By default, every new scene contains a Directional Light represents the sunlight/moonlight.

Property	Function
Color	Light color
Intensity	Light intensity value

Note

The direction of light is controlled by the rotation property of the object it attached to.

Shadows

IGE uses a technique called shadow mapping to render real-time shadows.

Shadow mapping uses textures called shadow maps. Shadow map texture resolution is set to 2048x2048 by default, and can be as largest as 4096x4096. Using larger texture result in higher quality, but it costs more VRAM and may decrease game performance.

To display shadow, ensure to have:

Shadow caster objects has enabled casting ability.
Shadow receiver has been enabled receiving ability.
Directional Light is ebabled and the light direction can cast shadow from shadow casters to shadow receiver.
Shadow parameters setup correctly.

When importing models, the ability to cast/receive shadow is disabled by default, to preserve best performance. To enable these abilities, go to Assets Browser, select the file to modify, in Assets windows, enable it’s flags accordingly then save it.

The shadow parameters can be adjusted with Environment component, attached to the root node of the hierarchy.

Property	Function
Color	Shadow color
Size	Shadow map texture size
Density	Shadow density
Wideness	Shadow wideness
Bias	Shadow Bias value

Note

With current implementation, only the first DirectionalLight can cast shadow because shadow transformation depends on the light direction.

Tip

Wideness and size are related, so wideness shoule be smaller as possible so it can improve shadow quality, or can use smaller size to improve performance.

Fogs

IGE provide basic fog setting to simulate fog.

Property	Function
Color	Fog color
Near	Fog near distance
Far	Fog far distance

Model

Models are files that contain data about the shape and appearance of 3D objects, such as characters, terrain, or environment objects. Model files can contain a variety of data, including meshes, materials, and textures. They can also contain animation data, for animated objects. Usually, models are created using an 3D modeling software, such as Blender®, Autodesk® Maya®, Autodesk® 3ds Max® …, and then import them into IGE.

IGE supports importing .dae and .fbx file formats. After importing to IGE, the files are converted to .pyxf format which is specially optimized for IGE. The game engine will automatically detect changes in the file system, and import model files accordingly.

Importing

In order to change importing options, go to Assets Browser, select the file to change settings, then look for Assets windows, then change the options when needed.

Property	Function
EXPORT_NAMES	Include meshes name in exported version
BASE_SCALE	Base scale factor (dae: 1.0, fbx: 100.0)
TRIANGLE_STRIP	[Optimize] Strip redundant trianges
OPTIMIZE_MESH	[Optimize] Optimize mesh
OPTIMIZE_VERTEX	[Optimize] Optimize vertex
OPTIMIZE_ANIMATION	[Optimize] Optimize animation
SHADER_MAKE_SHADOW	Enable shadow casting
SHADER_RECEIVE_SHADOW	Enable shadow receiving
SHADER_VERTEX_COLOR	Enable vertex color
SHADER_NUM_DIR_LAMP	Number of directional light
SHADER_NUM_POINT_LAMP	Number of point light
SHADER_NUM_SPOT_LAMP	Number of spot light
EMBEDDED_ANIMATION	Embbed animation, or build saparate anim file

Using Model

Model can be dragged to the Scene View to create scene object. Also, it can be attached to Figure or EditableFigure components of an empty object.

Figure component is used to render ‘fixed’ model, wothout ability of modifying mesh structures. It is the fasted way to render model using IGE. EditableFigure is used in case model’s mesh need to be changed at run time.

Property	Function
Path	Path to the model file
Fog	Enable/disable fog
DoubleSide	Enable/disable double side rendering
FFCulling	Enable/disable front-face culling
Z-Test	Enable/disable depth testing
Z-Write	Enable/disable depth writing
ScissorTest	Enable/disable scissor test
Update Ratio	Updating ratio, used to control animation speed
Mesh	List of meshes included in the model file
Material	List of materials included in the model file

For more details of scripting API, please refer to Python API Document.