3D Platformer GameDev Series – Weekly Blog #8: Health System and Player Knockback

Hey everyone! Whoa… It’s been about two months since I started this weekly blog series and the 3D Platformer Udemy Course. I feel that I am now heading into the bulk of the course material where the coding and logic is starting to get a bit more complicated to grasp – you may realize this too (if you have been following this blog series all along) when I attempt to explain how to implement player knockback today.

Before I dive right into the main content of my post, there is a key concept that I would like to mention again as it is becoming more evident when making a game in Unity and programming in C#:

“Individual scripts should only handle their individual elements.” – James Doyle

This concept was introduced earlier when the ‘GameManager’ script was created. You may recall that this script deals with everything that happens at the broader game level. However, that’s not to say that we cannot create – as we have done – instances of individual scripts and functions within them to call or be called by other scripts. We saw how important this was for the first time when player respawn was implemented and then again when checkpoints were added. This keeps the script and coding logic much more easy to read and follow! So as I progress further in the course, I will point this out less; by now, you should be able to see clearly how scripts, in a sense, interact with one another.

Now, onto the main topics of this post. The first thing is to create a health system. While it may be tempting to create it in the GameManager script, as I had just reminded everyone, we would want a separate or individual script for handling and managing the health system instead:

HealthManager script

The health system is really simple to set up as you can see from above. And because the script is set up as an instance, the ResetHealth function can then be called in the ‘GameManager’ script whenever the player respawns:

GameManager script updated

Now, something is needed to reduce the player’s health and to call the ‘Hurt’ function in the HealthManager script. For this, let’s add a spike trap to the game!

Spikes (add to game scene)

Just as we did with the Killzone created earlier and the checkpoints added before, for an interactable object such as these spikes, a box collider is added and the “Is Trigger” enabled to allow the following “HurtPlayer” script attached to the spikes object to work:

HurtPlayer script

Excellent! The only thing left to do now is to set up the player knockback when the player gets hurt. For this, we turn back to the ‘PlayerController’ script. Yes, you read right… I didn’t think we would have to turn back to the PlayerController script either…


Oh my… Did you understand all of that? It took some time for me afterwards, but if I were to try to come up with this logic myself, I honestly don’t think I would have been able to. And as an aside, this is one thing that especially bothers me sometimes. That is, for someone like myself who is not naturally good at programming and logic, it bothers me when I understand some aspect of coding only afterwards in hindsight. Although, I do believe that there are always more than one ways of doing or solving something. That being said, can anyone think of another way to implement player knockback? 🤔


Anyway, that’s it for this week’s blog! I hope you enjoyed the read. Stay tuned for next week when I make our robot player temporarily invincible and flash after getting hurt!

– Taklon

One thought on “3D Platformer GameDev Series – Weekly Blog #8: Health System and Player Knockback

  1. You’re making consistent progress! You’re right, it was complicated, but you explained it well.

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