add lightmap_fragment.glsl

src/renderers/shaders/ShaderChunk/lightmap_fragment.glsl

@@ -0,0 +1,5 @@
+#ifdef USE_LIGHTMAP
+
+	reflectedLight.indirectDiffuse += PI * texture2D( lightMap, vUv2 ).xyz * lightMapIntensity; // factor of PI should not be present; included here to prevent breakage
+
+#endif