Frost Grenade
I wanted to create an effect where I could showcase different techniques, dive deeper into Blueprints and improve my ability to deliver complete, game ready effects. The result was a frost attack type grenade which could immobilize enemies, shatter them into several pieces and remove them from being a threat.
Interactable version
Freeze effect
Freeze Material
The first step in this effect is the actual freezing of the enemies. Thanks to my friend Jona Marklund, I got to borrow a really suitable character for this. Check out his portfolio HERE!
The Freeze material turned out to be good practice in vector math. It basically takes the point of the explosion and applies a mask on the area of the mesh facing away or towards this point. This mask then lerps all the ice textures in and enable the vertex offset icicles which make the mesh look frozen.
Some downsides to this method is that the extruded icicles lacks angle corrected normals, but you hardly notice this with subsurface scattering and when everything is exploding.
Material Graph
Blueprints
Throwable Grenade Blueprint
To the left is the throwable grenade. This blueprint triggers the various effects that can be seen: First, the actual shattering of the grenade mesh, then the build up and finally the explosion. The main take away of this blueprint is that the grenade needs to know which enemies it has hit in order for them to be frozen. This is done via a sphere trace around the point of explosion. If something gets hit within the sphere trace, a custom event is cast to the hit actors.
Freezable character Blueprint
This blueprint takes care of the freezing and shattering of the enemy actors.
- Start the idle animation at a random frame.
- If it was hit, slow down the animation to a halt with a timeline param, scale up the freeze effect.
- Switch to the destructible mesh and apply an impulse at the grenade’s location which makes the pieces go flying.
VFX Controller Blueprint
This blueprint is spawned after a timer has run out in the grenade. It triggers the build up particle effect, and triggers the explosion particle system. The unstable ice crystal at the center is also animated here.