public void addDefine(String paramName, VarType paramType) {
        if (techniqueDef.getShaderParamDefine(paramName) == null) {
            techniqueDef.addShaderParamDefine(paramName, paramType, paramName.toUpperCase());
        }
    }
Adds a define to the technique def

@param paramName the name of the material parameter
@param paramType the type of the material parameter
jme3-core/src/plugins/java/com/jme3/material/plugins/ShaderNodeLoaderDelegate.java