Before relying on Visible Invisibility Shaders in player battles or survival matches, test the effect in a safe world to see how hidden targets stand out against different backgrounds.
Checking the Effect on Yourself or a Mob
1. Load into a singleplayer world and grab a vanilla Potion of Invisibility or Splash Potion of Invisibility.
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3. Drink the potion and press your Toggle Perspective key (F5 by default) to view your own character, or throw a splash potion onto a nearby mob.
4. Watch the swirling potion particles around the invisible model. With the core-shader active, those particles pop out sharply against the surrounding background like a TrueSight marker instead of blending into dark terrain.
Comparing Against Normal Vanilla Rendering
1. Open Options > Resource Packs while facing the invisible mob, move the pack out of the active column, and click Done.
2. Note how faint the standard translucent potion swirls appear, then move the pack back to the active column to confirm the TrueSight tweak is working properly before joining a match.