question: specifies the model 's light direction . concode_field_sep OGLStackHandler lightingStackHandler concode_elem_sep long frameID concode_elem_sep Material lightMaterial concode_elem_sep Vec4 lightDirection concode_field_sep void beginLighting concode_elem_sep void apply concode_elem_sep void endLighting concode_elem_sep void setLightMaterial concode_elem_sep void applyStandardLightMaterial concode_elem_sep Material getLightMaterial concode_elem_sep void applyStandardLightDirection concode_elem_sep void applyStandardLightModel concode_elem_sep Vec4 getLightDirection concode_elem_sep void applyStandardShadeModel
target: void function ( Vec4 arg0 ) { if ( arg0 == null ) { String loc0 = Logging . getMessage ( "srini_string" ) ; Logging . logger ( ) . severe ( loc0 ) ; throw new IllegalStateException ( loc0 ) ; } this . lightDirection = arg0 ; }