protected void appendOutput(StringBuilder source, String globalOutputName, ShaderNodeVariable var) {
        appendIndent(source);
        source.append(globalOutputName);
        source.append(" = ");
        source.append(var.getNameSpace());
        source.append("_");
        source.append(var.getName());
        source.append(";\n");
    }
Appends an output assignment to a shader globalOutputName =
nameSpace_varName;

@param source the source StringBuilder to append the code.
@param globalOutputName the name of the global output (can be gl_Position
or gl_FragColor etc...).
@param var the variable to assign to the output.
jme3-core/src/main/java/com/jme3/shader/Glsl100ShaderGenerator.java