Howto:Animate models: Difference between revisions

===Axis===

An axis part is required in every animation that involves a rotating or moving thing.

   <axis>

   <x>0</x>

   <z>0</z>

   </axis>

The axis are similar to the ones of the 3D model. There is a difference between rotation and translation:

You could also define two points, between which FlightGear will calculate the correct axis. This makes the use of a [[#Center|<nowiki><center></nowiki>]] tag redundant! Such coordinates are extremely useful for animating control surfaces (rudder, elevators etc.).

   <axis>   

   <x1-m> 4.9</x1-m>

   <z2-m>-0.5</z2-m>

   </axis>

===Center===

Various animations ([[#Rotate|rotate]], [[#Spin|spin]]) move around a center point.

   <x-m>-1.50</x-m>

   <y-m> 1  </y-m>

   <z-m> 0.25</z-m>

The axis are similar to the ones of the 3D model, so finding coordinates is easily done in 3D modeling software.

The example below is true when n1 has a value greater than 25.

   <condition>

   <greater-than>

   </greater-than>

   </condition>

Then there are some special tags:

In the example below, the condition is true when either n1 is greater than 25% or equal to 0%.

   <condition>

   <or>

   <or>

   </condition>

An example of implementation into an animation looks as follows:

  <animation>

   <object-name>Object</object-name>

   </greater-than>

   </condition>

   <x-m>-1.50</x-m>

   <y-m> 1  </y-m>

   <z-m> 0.25</z-m>

   <axis>

   <x>0</x>

   </axis>

  </animation>

===Interpolation===

For non-fixed factors, an interpolation "table" can be created.  

   <interpolation>

   <entry>

   </entry>

   </interpolation>

The lines above represent the following table:

With a name animation, you can group multiple objects.  

  <animation>

   <name>Collection1</name>

   <object-name>Object3</object-name>

  </animation>

The example above creates a "virtual object" with the name Collection1. In animation, we can animate this group of objects, by using:

  <object-name>Collection1</object-name>

===Object-name===

==Animation types==

===Alpha-test===

  <animation>

   <type>alpha-test</type>

   <alpha-factor>0.01</alpha-factor>

  </animation>

===Billboard===

This faces an object towards the viewer. Often used on 2D objects, like clouds, trees and lights.

  <animation>

   <type>billboard</type>

   <spherical type="bool">true</spherical>

  </animation>

* '''spherical:'''

Used to scale an object, based on the distance to the viewer.

  <animation>

   <type>dist-scale</type>

   </interpolation>

  </animation>

===Enable-hot===

Scenery objects are automatically defined as solid by FlightGear, meaning that an aircraft can taxi on them and/or crash when touching. For certain objects (groundmarkings, beacon light-beams etc.) this might be an unwanted feature. The solidness can be disabled with the following animation:

  <animation>

   <object-name>Object</object-name>

   <enable-hot type="bool">false</enable-hot>

  </animation>

* '''enable-hot:''' can be either true or false. Remember that objects are automatically solid, so it should not be nesecarily to set this at all when wanting solidness.

===Flash===

  <animation>

   <type>flash</type>

   <min>0.0</min>

   <max>1.0</max>

   <x-m>0.0</x-m>

   <y-m>0.0</y-m>

   <z-m>0.0</z-m>

   <axis>

   <x>0.0</x>

   </axis>

  </animation>

*'''offset:'''

===Interactions===

  <animation>  

   <type>interaction</type>  

   <interaction-type>carrier-wire</interaction-type>  

  </animation>  

*'''interaction-type:''' can have the following values:

Used for the [[Livery over MP]] system.

  <animation>  

   <type>material</type>  

   <texture>KLM.png</texture>  

  </animation>

====Illumination====

{{Main article|Howto: Illuminate faces}}

  <animation>

   <type>material</type>

   </emission>

  </animation>

Emission colors are multiplied by the factor-prop value. 1 is maximum coclor intensity, while 0 is the minimum. Colors are calculated according to the [http://en.wikipedia.org/wiki/RGB_color_model RGB color model].

===Noshadow===

  <animation>

   <type>noshadow</type>

   <object-name>Object</object-name>

  </animation>

===Pick===

To prevent objects -like instruments- being drawn when the aircraft is actually too far away for them to be seen anyway, a range animation is used.  

  <animation>

   <type>range</type>

   <max-m>30</max-m>

  </animation>

* '''min-m:''' the shortest distance (in meters) from the object center at which it is visible.

The animation code will look like this:

  <animation>

   <type>range</type>

   <max-property>sim/rendering/static-lod/bare</max-property>

  </animation>

You can have both ranges (max and min) bound to a property, or just one of them.

One of the most important and frequently used animations of all. It rotates an object to an absolute position in degrees, as provided by the property-value.

  <animation>

   <object-name>Object</object-name>

   <property>suface-positions/left-aileron-pos-norm</property>

   <factor>25</factor>

   <x-m>-1.50</x-m>

   <y-m> 1  </y-m>

   <z-m> 0.25</z-m>

   <axis>

   <x>0</x>

   </axis>

  </animation>

* '''factor:''' is optional.

A scale animation scales (resizes) an object. This can be either property-value dependant (first example) or a fixed scale (second example).

  <animation>

   <type>scale</type>

   <z-factor>2.0</z-factor>

  </animation>

* ?-min: the mimimum scale factor for each axis. If the property value would result in a smaller factor than this setting, the scale animation will hold.

* ?-factor: the scale factor for each axis (factor*property=scale factor).

  <animation>

   <type>scale</type>

   <z-offset>0.5</z-offset>

  </animation>

* x.offset: the scale factor.

This animation selects (or unselects) objects when certain conditions are true (or false). The example below shows the object when the n1 of engine[1] is higher than 25%.

  <animation>

   <object-name>Object</object-name>

   </condition>

  </animation>

===Shader===

  <animation>

   <type>shader</type>

   <object-name>Object</object-name>

  </animation>

* '''shader:'''  

Very similar to [[#Rotate|rotate]], but the property provides a value in revolutions per minute (RPM) rather than an absolute position in degrees, and offset cannot be used.

  <animation>

   <object-name>Object</object-name>

   <property>engines/engine[0]/n1</property>

   <factor>25</factor>

   <x-m>-1.50</x-m>

   <y-m> 1  </y-m>

   <z-m> 0.25</z-m>

   <axis>

   <x>0</x>

   </axis>

  </animation>

* '''factor:''' is optional.

A very important animation for cockpits! This animation moves textures over a surface.

  <animation>

   <type>textranslate</type>

   </axis>

  </animation>

* '''factor:'''

Swtiches between objects at specified intervals. This example switches between a lights-on model and a lights-off model. Lights on are shown 0.2 seconds, while lights off are displayed for 0.8 seconds.

  <animation>

   <type>timed</type>

   <branch-duration-sec>0.2</branch-duration-sec>

  </animation>

===Translate===

The same as [[#Textranslate|textranslate]], but this animation moves a whole object (so including fixed textures). The example below will move an object 5 meters in the y-direction.

  <animation>

   <type>translate</type>

   </axis>

  </animation>

[[Category:Aircraft enhancement|Animate models]]