From BlenderWiki

Jump to: navigation, search
Blender3D FreeTip.gif
IMPORTANT! Do not update this page!
We have moved the Blender User Manual to a new location. Please do not update this page, as it will be locked soon.

Track To Constraint

Description

The Track To constraint applies rotations to its owner, so that it always points a given “To” axis towards its target, with another “Up” axis permanently maintained as much aligned with the global Z axis (by default) as possible. This tracking is similar to the "billboard tracking" in 3D (see note below).

This is the preferred tracking constraint, as it has a more easily controlled constraining mechanism.

This constraint shares a close relationship to the Inverse Kinematics constraint in some ways. It is very important in rig design, and you should be sure to read and understand the 2.49 BSoD tracking tutorial, as it centers around the use of both of these constraints.

Blender3D FreeTip.gif
Billboard tracking
The term “billboard” has a specific meaning in real-time CG programming (i.e. video games!), where it is used for plane objects always facing the camera (they are indeed “trackers”, the camera being their “target”). Their main usage is as support for tree or mist textures: if they were not permanently facing the camera, you would often see your trees squeezing to nothing, or your mist turning into a millefeuille paste, which would be funny but not so credible.


Options

Track To panel
Targets
This constraint uses one target, and is not functional (red state) when it has none.
Bone
When Target is an armature, a new field for a bone is displayed.
Head/Tail
When using a bone target, you can choose where along this bone the target point lies.
Vertex Group
When Target is a mesh, a new field is display where a vertex group can be selected.
To
The tracking local axis (Y by default), i.e. the owner’s axis to point at the target. The negative options force the relevant axis to point away from the target.
Up
The “upward-most” local axis (Z by default), i.e. the owner’s axis to be aligned (as much as possible) with the global Z axis (or target Z axis, when the Target button is enabled).
Target Z
By default, the owner’s Up axis is (as much as possible) aligned with the global Z axis, during the tracking rotations. When this button is enabled, the Up axis will be (as much as possible) aligned with the target’s local Z axis…
Space
This constraint allows you to choose in which space to evaluate its owner’s and target’s transform properties.
Exclamation mark.png
If you choose the same axis for To and Up, the constraint will not be functional anymore (red state).




Blender3D FreeTip.gif
This is the old manual!
For the current 2.7x manual see http://www.blender.org/manual/


User Manual

World and Ambient Effects

World

Introduction
World Background

Ambient Effects

Mist
Stars (2.69)


Game Engine

Introduction

Introduction to the Game Engine
Game Logic Screen Layout

Logic

Logic Properties and States
The Logic Editor

Sensors

Introduction to Sensors
Sensor Editing
Common Options
-Actuator Sensor
-Always Sensor
-Collision Sensor
-Delay Sensor
-Joystick Sensor
-Keyboard Sensor
-Message Sensor
-Mouse Sensor
-Near Sensor
-Property Sensor
-Radar Sensor
-Random Sensor
-Ray Sensor
-Touch Sensor

Controllers

Introduction
Controller Editing
-AND Controller
-OR Controller
-NAND Controller
-NOR Controller
-XOR Controller
-XNOR Controller
-Expression Controller
-Python Controller

Actuators

Introduction
Actuator Editing
Common Options
-2D Filters Actuator
-Action Actuator
-Camera Actuator
-Constraint Actuator
-Edit Object Actuator
-Game Actuator
-Message Actuator
-Motion Actuator
-Parent Actuator
-Property Actuator
-Random Actuator
-Scene Actuator
-Sound Actuator
-State Actuator
-Steering Actuator
-Visibility Actuator

Game Properties

Introduction
Property Editing

Game States

Introduction

Camera

Introduction
Camera Editing
Stereo Camera
Dome Camera

World

Introduction

Physics

Introduction
Material Physics
No Collision Object
Static Object
Dynamic Object
Rigid Body Object
Soft Body Object
Vehicle Controller
Sensor Object
Occluder Object

Path Finding

Navigation Mesh Modifier

Game Performance

Introduction
System
Display
Framerate and Profile
Level of Detail

Python API

Introduction
Bullet physics
VideoTexture

Deploying

Standalone Player
Licensing of Blender Game

Android Support

Android Game development