three.js/src/renderers/shaders/ShaderLib/meshlambert_frag.glsl

uniform vec3 diffuse;
uniform vec3 emissive;
uniform float opacity;

varying vec3 vLightFront;

#ifdef DOUBLE_SIDED

	varying vec3 vLightBack;

#endif

#include <common>
#include <color_pars_fragment>
#include <uv_pars_fragment>
#include <uv2_pars_fragment>
#include <map_pars_fragment>
#include <alphamap_pars_fragment>
#include <aomap_pars_fragment>
#include <lightmap_pars_fragment>
#include <emissivemap_pars_fragment>
#include <envmap_pars_fragment>
#include <bsdfs>
#include <ambient_pars>
#include <lights_pars>
#include <fog_pars_fragment>
#include <shadowmap_pars_fragment>
#include <shadowmask_pars_fragment>
#include <specularmap_pars_fragment>
#include <logdepthbuf_pars_fragment>

void main() {

	vec4 diffuseColor = vec4( diffuse, opacity );
	ReflectedLight reflectedLight = ReflectedLight( vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ) );
	vec3 totalEmissiveLight = emissive;

	#include <logdepthbuf_fragment>
	#include <map_fragment>
	#include <color_fragment>
	#include <alphamap_fragment>
	#include <alphatest_fragment>
	#include <specularmap_fragment>
	#include <emissivemap_fragment>

	// accumulation
	reflectedLight.indirectDiffuse = getAmbientLightIrradiance( ambientLightColor );

	#include <lightmap_fragment>

	reflectedLight.indirectDiffuse *= BRDF_Diffuse_Lambert( diffuseColor.rgb );

	#ifdef DOUBLE_SIDED

		reflectedLight.directDiffuse = ( gl_FrontFacing ) ? vLightFront : vLightBack;

	#else

		reflectedLight.directDiffuse = vLightFront;

	#endif

	reflectedLight.directDiffuse *= BRDF_Diffuse_Lambert( diffuseColor.rgb ) * getShadowMask();

	// modulation
	#include <aomap_fragment>

	vec3 outgoingLight = reflectedLight.directDiffuse + reflectedLight.indirectDiffuse + totalEmissiveLight;

	#include <envmap_fragment>

	gl_FragColor = vec4( outgoingLight, diffuseColor.a );

	#include <tonemapping_fragment>
	#include <encodings_fragment>
	#include <fog_fragment>
	#include <premultiplied_alpha_fragment>

}