Animating 3D Characters/Objects in SceneKit

📚 Official Books 3D iOS Games by Tutorials
1

I really enjoyed the book and I completed all the tutorials. However, there is one topic I didn’t see covered that I’m curious about. What if one wanted to have an “animated” 3D object in a scene. An example: I want to create a tank with a rotating turret. The tank should move around the scene as one object, but the turret is able to rotate in any direction and possibly even the gun could raise & lower. How would one approach such a task? Would you create multiple nodes and combine them with a joint? Or, I recall from SpriteKit (though it has been a long while) that there is a way to have an “animated” spritekit node. Is there an equivalent method in SceneKit?

Just hoping to hear any thoughts/idea on an approach… not detailed code examples (unless you’re feeling generous!) or a link to another tutorial/example.

Thanks,
Tom

2

I can point you in the direction to study the Apple™ “Fox” demo.
Go to the Apple Developer page, download the “FoxBuildingaSceneKitGamewiththeXcodeSceneEditor” Study the “Character.swift” file. it demonstrates how they animate a Fox character.

Here is the character animation implementation it uses a 3D model (fox) that was animated in an external application.
// MARK: Configure animations

        // Some animations are already there and can be retrieved from the scene
        // The "walk" animation is loaded from a file, it is configured to play foot steps at specific times during the animation
        
        characterTopLevelNode.enumerateChildNodes { (child, _) in
            for key in child.animationKeys {                  // for every animation key
                let animation = child.animation(forKey: key)! // get the animation
                animation.usesSceneTimeBase = false           // make it system time based
                animation.repeatCount = Float.infinity        // make it repeat forever
                child.addAnimation(animation, forKey: key)             // animations are copied upon addition, so we have to replace the previous animation
            }
        }
        
        walkAnimation = CAAnimation.animationWithSceneNamed("game.scnassets/walk.scn")
        walkAnimation.usesSceneTimeBase = false
        walkAnimation.fadeInDuration = 0.3
        walkAnimation.fadeOutDuration = 0.3
        walkAnimation.repeatCount = Float.infinity
        walkAnimation.speed = Character.speedFactor
        walkAnimation.animationEvents = [
            SCNAnimationEvent(keyTime: 0.1) { (_, _, _) in self.playFootStep() },
            SCNAnimationEvent(keyTime: 0.6) { (_, _, _) in self.playFootStep() }]
    }
3

Thank you! I will check out that example.

4

Holy moly! This sample is amazing! I haven’t looked at the code yet, but I built it and installed on my iPhone. And I was blown away. Thank you for recommending it.

5

There are a few more project examples. This one is better…
BadgerAdvancedRenderinginSceneKit"

Run on a device or Mac (to slow on the simulator)

Also watch this video, skip to time code 29:40. Then after you watch it, go back and watch to entire vid (apologies for the strong french accent Lol!)

6

Oh very cool. I have put this one on my phone as well. You say there is a video as well?

7

https://developer.apple.com/videos/play/wwdc2016/609/

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