Turn On True Light Shaders Through Iris or OptiFine

True Light Shaders is a shader pack, so it needs a shader loader such as Iris or OptiFine before it does anything. Vanilla Minecraft cannot run shader packs on its own.

Loading the Pack

1. Launch Minecraft with your shader loader active. Look for a Shader Packs or Shaders button in the video menu to confirm it is loaded.

2. Go to Options > Video Settings and open the shader menu.

3. Use the button that opens the shader pack folder. This is the shaderpacks folder inside your game directory, not the resourcepacks folder.

4. Make sure the True Light Shaders file is in that folder, then return to the game.

5. Select True Light Shaders from the list and click Apply or Done.

The first load can take a moment while the shaders compile.

Checking That It Worked

The pack is designed to keep the original vanilla art style, so don't expect a dramatic new look. To confirm it is running:

• Stand near a tall structure or a tree in daylight.
• Look for soft shadows falling across the ground and nearby blocks.
• Turn the pack off in the shader menu and compare the same view.

If the scene looks flat with the pack off and shaded with it on, the pack is working. If nothing changes, check that the file is in shaderpacks and that your loader is actually running.