protected String getAppendableNameSpace(ShaderNodeVariable var) {
        String namePrefix = var.getNameSpace() + "_";
        if (namePrefix.equals("Attr_") || namePrefix.equals("WorldParam_") || namePrefix.equals("MatParam_")) {
            namePrefix = "";
        }
        return namePrefix;
    }
returns the name space to append for a variable. 
Attributes, WorldParam and MatParam names space must not be appended
@param var the variable
@return the namespace to append for this variable
jme3-core/src/main/java/com/jme3/shader/Glsl100ShaderGenerator.java