Creating Weapon Shaders
Step 1. Render Weapon with Stencil
First, render the weapon model with stencil buffer configuration:
stencilRef: 1
stencilZPass: ReplaceStencilOp
Step 2. Render Outline Model
Scale the model up with a solid color or use a vertex shader to displace the vertices:
vec3 displacedPosition = position + normal * 0.1;
Step 3. Stencil Buffer Magic
The stencil buffer is used to exclude the base gun model, allowing only outside pixels to be drawn:
side: DoubleSide,
stencilWrite: true,
stencilRef: 1,
stencilFunc: NotEqualStencilFunc
Step 4. Glow Sprite
Add a simple 2D sprite image using the same stencil buffer magic to create a glow effect.
Step 5. Fresnel
Add a Fresnel shader to the base weapon. Use PointLight & Bloom for added effect.