Making OutlinePass Outlines Fully Opaque in Three.js

Based on your issue with the OutlinePass in Three.js, it appears that your outlines are being affected by the background color, suggesting they might be using a blending mode that's causing transparency effects.

Potential Solutions

When working with the OutlinePass, you can try these approaches to make your outlines fully opaque regardless of background:

1. Adjust the renderer's clear color:
   You can use the setClearColor method of the WebGLRenderer to set a specific background color:

   JAVASCRIPTCopied
   renderer.setClearColor(0xffffff, 1); // White background with full opacity

2. Modify OutlinePass parameters:
   The OutlinePass has several parameters that control its appearance. Try adjusting:

   JAVASCRIPTCopied
   outlinePass.edgeStrength = 10; // Increase for stronger edges
   outlinePass.edgeGlow = 0; // Reduce glow effect
   outlinePass.edgeThickness = 1; // Control thickness
   outlinePass.pulsePeriod = 0; // Disable pulsing
   outlinePass.visibleEdgeColor.set(0x0000ff); // Blue color
   outlinePass.hiddenEdgeColor.set(0x0000ff); // Same color for hidden edges

3. Consider alternative materials:
   If the OutlinePass doesn't provide the desired result, you might want to explore alternative approaches using materials:

   • Using a LineBasicMaterial for manual outlines
   • Creating a second, slightly larger mesh with a MeshBasicMaterial behind your object

4. Check blending modes:
   The issue might be related to how the outline is being blended with the background. If you have access to the OutlinePass shader code, you might need to modify how it handles transparency.

Remember that the OutlinePass is a post-processing effect, so it's applied after the scene is rendered, which can sometimes lead to these kinds of visual artifacts depending on the background.