Fast enemies ignoring shield powerup - collision detection fix
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GameDev_Hunter
Posted on July 20, 2025 • Intermediate
🛡️ Shield powerup not working with fast enemies!
Hey everyone! I’m working on a dodge-the-enemies game and I’m having a really frustrating issue with my shield powerup system:
- I have enemies that move really fast using glide blocks
- When the player has a shield powerup active, it should protect them
- But the fast enemies are completely ignoring the shield and still causing damage!
- Slower enemies work fine with the shield, but the homing enemies just pass right through
I don’t want to slow down the enemies because that would make the game too easy. How can I fix the collision detection so the shield actually works? 😭
CollisionExpert_Maya
Replied 2 hours later • ⭐ Best Answer
I know exactly what’s happening @GameDev_Hunter! This is a classic fast-moving sprite collision issue. The problem is that your enemies are moving so fast they “skip over” the collision detection.
🔍 Why Fast Enemies Ignore Collisions
When sprites move too quickly, they can jump from one side of another sprite to the other in a single frame, never actually “touching” during collision detection:
🛠️ Solution 1: Continuous Collision Detection
Instead of just checking if sprites are touching, check the path between positions:
// In your enemy sprite define check collision with shield set [collision detected v] to [false] set [check x v] to (x position) set [check y v] to (y position) // Check multiple points along the movement path repeat [10] go to x: (check x) y: (check y) if <<touching [Player v]?> and <(shield active) = [true]>> then set [collision detected v] to [true] // Handle shield collision broadcast [shield hit v] stop [this script v] end change [check x v] by ((target x - (x position)) / [10]) change [check y v] by ((target y - (y position)) / [10]) end
🎯 Solution 2: Smaller Movement Steps
Break down fast movement into smaller steps with collision checks:
// Replace your glide block with this define move to player with collision check set [steps v] to [20] // More steps = better collision detection set [step x v] to (((Player x) - (x position)) / (steps)) set [step y v] to (((Player y) - (y position)) / (steps)) repeat (steps) change x by (step x) change y by (step y) // Check collision after each small step if <touching [Player v]?> then if <(shield active) = [true]> then // Shield blocks the enemy broadcast [shield hit v] point towards [Player v] move [-20] steps // Bounce back stop [this script v] else // No shield, damage player broadcast [player hit v] stop [this script v] end end end
🔧 Solution 3: Distance-Based Detection
Use distance calculations for more reliable detection:
// Custom block: check shield collision by distance define check shield collision set [distance to player v] to (distance to [Player v]) if <(distance to player) < [30]> then // Adjust collision radius if <(shield active) = [true]> then // Shield effect set effect [brightness v] to [50] play sound [shield block v] point towards [Player v] move [-50] steps // Bounce away wait [0.1] seconds clear graphic effects else // Normal collision broadcast [player damaged v] hide end end
🛡️ Complete Shield System
Here’s how to set up the complete shield powerup system:
// In Player sprite - Shield activation when I receive [shield powerup collected v] set [shield active v] to [true] set [shield timer v] to [300] // 5 seconds at 60 FPS set effect [ghost v] to [30] // Visual feedback play sound [shield activate v] // Shield timer countdown when flag clicked forever if <(shield active) = [true]> then change [shield timer v] by [-1] if <(shield timer) < [1]> then set [shield active v] to [false] clear graphic effects play sound [shield deactivate v] end end end // When shield is hit when I receive [shield hit v] if <(shield active) = [true]> then play sound [shield block v] // Optional: reduce shield duration change [shield timer v] by [-60] // Lose 1 second end
The key is checking collision multiple times during movement, not just once per frame! 🎉
GameDev_Hunter
Replied 1 hour later
@CollisionExpert_Maya This is incredible! 🤩
I implemented the smaller movement steps solution and it works perfectly! The shield now properly blocks even the fastest homing enemies. The distance-based detection is also a great backup method.
Thank you so much for the detailed explanation and multiple solutions! My game feels so much more polished now! 🛡️✨
PowerupDev_Chris
Replied 30 minutes later
Great solution @CollisionExpert_Maya! 👏 I’d like to add some tips for making powerup systems even better:
- Visual feedback: Make the shield effect clearly visible with particle effects or glowing outlines
- Audio cues: Different sounds for shield activation, blocking, and deactivation help players understand the system
- Shield durability: Consider making shields block a certain number of hits instead of just time-based
- Cooldown system: Prevent shield spam by adding a cooldown period after it expires
These details make the difference between a good game and a great one! 🎮
Vibelf_Community
Pinned Message • Moderator
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