         EndPrimitive();
     }
 
-fragment =
+fragment41core =
     #version 410
-    varying lowp vec4 f_color;
-    varying lowp vec3 f_normal;
-    varying lowp vec3 f_vertex;
+    in lowp vec4 f_color;
+    in lowp vec3 f_normal;
+    in lowp vec3 f_vertex;
+
+    out vec4 frag_color;
 
     uniform mediump vec4 u_ambientColor;
     uniform highp vec3 u_lightPosition;


    uniform highp mat4 u_normalMatrix;

    attribute highp vec4 a_vertex;
    attribute lowp vec4 a_color;
    attribute lowp vec4 a_material_color;
    attribute highp vec4 a_normal;
    attribute highp vec2 a_line_dim;  // line width and thickness
    attribute highp int a_extruder;
    attribute highp int a_line_type;

    varying lowp vec4 v_color;

    varying highp vec3 v_vertex;
    varying highp vec3 v_normal;
    varying lowp vec2 v_line_dim;
    varying highp int v_extruder;
    varying highp vec4 v_extruder_opacity;
    varying int v_line_type;

    varying lowp vec4 f_color;
    varying highp vec3 f_vertex;
    varying highp vec3 f_normal;
    varying highp int f_extruder;

    void main()
    {

[shaders]
vertex41core =
    #version 410
    uniform highp mat4 u_modelMatrix;
    uniform highp mat4 u_viewProjectionMatrix;
