Questions About Implementing Complex Animations in SwiftUI

🎤 General Discussion Swift
1

Hi Kodeco Community,

I’m working on a project using SwiftUI and need some help with implementing complex animations. I have a few specific questions:

Custom Timing Curves: How can I create and apply custom timing curves in SwiftUI animations?
Synchronizing Animations: What is the best way to synchronize multiple animations?
Performance Optimization: Any tips on optimizing performance for complex animations?
I appreciate any advice or resources you can share. Thanks in advance for your help!

3

Hello,

Working with animations in SwiftUI can be quite powerful, but also challenging when it comes to creating complex and smooth animations. Here are some insights on the topics you’ve mentioned:

  1. Custom Timing Curves
    SwiftUI provides built-in timing curves for animations, but if you need custom timing curves, you can use the Animation struct with a custom TimingCurve. Here’s how you can create and apply custom timing curves: import SwiftUI

// Define a custom timing curve
let customTimingCurve = Animation.timingCurve(
0.25, // control point 1 x
0.1, // control point 1 y
0.25, // control point 2 x
1.0, // control point 2 y
duration: 1.0 // animation duration
)

// Apply the custom timing curve to an animation
struct ContentView: View {
@State private var isAnimating = false

var body: some View {
    VStack {
        Rectangle()
            .fill(Color.blue)
            .frame(width: isAnimating ? 200 : 100, height: 100)
            .animation(customTimingCurve)
        
        Button("Animate") {
            isAnimating.toggle()
        }
    }
}

}
In this example, Animation.timingCurve(::::duration:) allows you to define a custom animation curve with two control points. Adjust these values to suit your animation needs.

  1. Synchronizing Animations
    To synchronize multiple animations, you can use the Animation struct’s delay parameter or use withAnimation blocks to trigger multiple animations simultaneously. Here are two approaches:

Using Delays: import SwiftUI

struct ContentView: View {
@State private var isAnimating = false

var body: some View {
    VStack {
        Rectangle()
            .fill(Color.blue)
            .frame(width: isAnimating ? 200 : 100, height: 100)
            .animation(.easeInOut.delay(0.1))
        
        Circle()
            .fill(Color.red)
            .frame(width: isAnimating ? 150 : 75, height: 150)
            .animation(.easeInOut.delay(0.2))
        
        Button("Animate") {
            isAnimating.toggle()
        }
    }
}

}
Using withAnimation: import SwiftUI

struct ContentView: View {
@State private var isAnimating = false

var body: some View {
    VStack {
        Rectangle()
            .fill(Color.blue)
            .frame(width: isAnimating ? 200 : 100, height: 100)
        
        Circle()
            .fill(Color.red)
            .frame(width: isAnimating ? 150 : 75, height: 150)
        
        Button("Animate") {
            withAnimation(.easeInOut(duration: 1.0)) {
                isAnimating.toggle()
            }
        }
    }
}

}
In the second approach, withAnimation is used to trigger animations for both the Rectangle and Circle simultaneously.

  1. Performance Optimization
    Optimizing animation performance is crucial for smooth and responsive UIs. Here are some tips:

Use .drawingGroup(): For complex views, especially when using shadows or layers, you might want to use .drawingGroup() to offload rendering to a separate layer. Rectangle()
.fill(Color.blue)
.frame(width: isAnimating ? 200 : 100, height: 100)
.drawingGroup()
Minimize View Hierarchy Complexity: Complex view hierarchies can impact performance. Simplify the hierarchy where possible.

Avoid Expensive Computations in Animations: Avoid performing heavy computations or updates inside the animation block. Move such operations outside of the animation context.

Use GeometryReader Sparingly: While GeometryReader is useful, it can be expensive if overused. Use it only when necessary and keep its usage minimal.

Profile with Instruments: Use Xcode Instruments to profile your app and identify performance bottlenecks related to animations.

Leverage Implicit Animations: Implicit animations are often more performant than explicit ones because they take advantage of system optimizations.

By applying these practices and leveraging SwiftUI’s powerful animation capabilities, you should be able to create smooth and efficient animations for your project.

Hope that helps!

Lhi Provider Portal

4

Hello,
Custom Timing Curves Official Site
To create and apply custom timing curves in SwiftUI, you can use the timingCurve method. This method allows you to define a cubic Bézier curve by specifying four control points. Here’s an example:

Swift

import SwiftUI

struct ContentView: View {
@State private var scale = 1.0

var body: some View {
    VStack {
        Circle()
            .scaleEffect(scale)
            .animation(
                .timingCurve(0.1, 0.75, 0.85, 0.35, duration: 2.0),
                value: scale
            )
        Button("Animate") {
            scale = scale == 1.0 ? 0.25 : 1.0
        }
    }
}

Best Regards
katty867