I’m stuck with a weird problem in Unity. My AI prefab works fine when I drag it into the scene editor. But when I try to spawn the same prefab during gameplay, things go wonky.
The main issue is with the ThirdPersonCharacter script on the AI. For some reason, the agent just keeps doing the idle animation. It seems like the CheckGroundStatus() function is messing up, especially this part:
myAnimator.applyRootMotion = false;
Instead of walking normally, the AI just slides to where it’s supposed to go. It’s like it can’t figure out it’s on the ground or something.
I’m scratching my head here. How can the same prefab act so differently when spawned vs placed in the editor? There’s gotta be a simple fix, but I’m drawing a blank. Any ideas what could be causing this?
I have seen this kind of issue before when a prefab behaves differently at runtime compared to when it’s placed in the editor. In my experience, the problem often lies in the timing and order of component initializations. When the prefab is spawned during gameplay, some components such as the Animator or the NavMeshAgent may not be ready immediately, resulting in misinterpretation of physical states. Adding a brief delay or checking that all components have been properly set up can help. Moreover, ensuring that the ground layer settings are correct and that no other scripts interfere with the initialization process has proven effective in resolving similar challenges.
hey, i’ve seen this too. maybe check your instantiate() call - runtime transforms can get borked. also ensure your navmesh is baked properly so the ai lands on it correctly. i fixed it by addin a short delay before the script kicks in. maybe worth a try.
I’ve run into this exact problem before, and it was a real head-scratcher. What fixed it for me was making sure the AI’s rigidbody was properly initialized at runtime. Sometimes Unity doesn’t set up physics components correctly when spawning prefabs dynamically.
Try adding a quick check in your spawn code to ensure the rigidbody is awake and has the correct settings. Something like:
Rigidbody rb = spawnedAI.GetComponent();
if (rb != null) {
rb.isKinematic = false;
rb.WakeUp();
}
This forces Unity to properly set up the physics state. Also, double-check that your AI’s collider isn’t intersecting with anything when it spawns. Even slight overlaps can cause weird behavior with ground detection.
If that doesn’t work, you might need to manually update the AI’s position using Transform.position instead of relying on physics for the first few frames after spawning. It’s a bit hacky, but it can get things working while you track down the root cause.
I’ve encountered a similar issue in my projects. One thing to check is the NavMeshAgent component on your AI prefab. Sometimes, when spawning at runtime, the agent doesn’t initialize properly on the NavMesh. Try adding a short delay after spawning before enabling the ThirdPersonCharacter script. Another potential culprit could be differences in physics settings between edit and play mode. Double-check your project’s physics settings, especially regarding collision detection. Lastly, ensure your spawn point is actually on the NavMesh - I’ve been caught out by that before. If none of these work, you might need to manually call NavMeshAgent.Warp() right after spawning to force proper placement.