uniform sampler2D ColorMapSampler; varying vec4 tPos; void main() { vec4 col = texture2D(ColorMapSampler, gl_TexCoord[0].st); if (col.a < 0.70) discard; float depth = 0.5 + tPos.z * 0.5; gl_FragColor = vec4(depth, 0.0, 0.0, 1.0); }