The BitBull Blog

Been continuing with the ‘conventional’ weapons after finishing the dreaded flamethrower. Next one on the list – grenade launcher. Every self-respecting shooter should have one!

Thankfully this was a lot simpler than the flamethrower. A large chunk of the time was spent tweaking the grenade explosion – I wanted something that gave an ‘area of effect’ type flash and wasn’t able to do this without using a custom shader. Luckily I was able to re-use the ‘smoke’ shader I talked about here. I may tweak this some more but am pretty happy with it as is.

There were also a few issues with the movement of the grenade itself. I started with a simple ‘real world’ type physics model, the same I use for the falling pickups. This looked good but it was too hard to tweak the range for the different weapon levels and also hard to predict the range a grenade would travel for the enemy AI.

I ended up using LERPing for the horizontal movement. This meant I could predict and tweak the travel distance with 100% accuracy. When the grenade hits an obstruction LERPing is turned off and motion reverts to a ‘real world’ model.

Vertical motion remains a ‘real world’ model but I cheat a bit here as well, starting with a lighter ‘gravity’ applied to the grenade and increasing the gravity as the grenade reaches the end of its horizontal travel. This enables me to get a nice arc of travel for the grenade whilst keeping things playable and predictable for the enemy AI.

I’m still undecided as to whether I should allow grenade ‘suicide’ or only allow enemy grenades to damage the player…

Dev Time: 1.5 days
Total Dev Time: approx 121 days

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