Animation

Sprite3D objects are essential to our game! We have learned how to manipulate them. However, we might want a more rich experience. Enter animation! To run a 3d animation, you can use the Animation3D and Animate3D objects. You then create an Animate3D action using the Animation3D object. Example:

// the animation is contained in the .c3b file
auto animation = Animation3D::create("orc.c3b");

// creates the Action with Animation object
auto animate = Animate3D::create(animation);

// runs the animation
sprite->runAction(RepeatForever::create(animate));

Run the example Programmer Guide Sample code to see this in action! Please keep in mind that 3D animations are exactly the same concepts as 2D. Please refer to Chapter 4 in this guide.

Multiple animations

What do you do when you want to run multiple animations at the same time? Using both the animation start time and animation length parameters you can create multiple animations. The unit for both parameters is seconds. Example:

auto animation = Animation3D::create(fileName);

auto runAnimate = Animate3D::create(animation, 0, 2);
sprite->runAction(runAnimate);

auto attackAnimate = Animate3D::create(animation, 3, 5);
sprite->runAction(attackAnimate);

In the above example there are two animations that get run. The first starts immediately and lasts for 2 seconds. The second starts after 3 seconds and lasts for 5 seconds.

Animation speed

The speed of the animation is a positive integer for forward while a negative speed would be reverse. In this case the speed is set to 10. This means that this animation can be considered to be 10 seconds in length.

Animation blending

When using multiple animations, blending is automatically applied between each animation. The purpose of blending is to create a smooth transition between effects. Given two animations, A and B, the last few frames of animation A and the first few frames of animation B overlap to make the change in animation look natural.

The default transition time is 0.1 seconds. You can set the transition time by using Animate3D::setTransitionTime.

Cocos2d-x only supports linear interpolation between keyframes. This fills in gaps in the curve to ensure a smooth path. If you use other interpolation methods in the model production, our built-in tool, fbx-conv will generate additional keyframes to compensate. This compensation is completed in accordance with the target frame. For more information on fbx-conv please refer to the section discussing it at the end of this chapter.