This: http://fabiensanglard.net/rayTracing_back_of_business_card/index.php http://fabiensanglard.net/rayTracing_back_of_business_card/i... is a perfect example

This: http://fabiensanglard.net/rayTracing_back_of_business_card/index.php http://fabiensanglard.net/rayTracing_back_of_business_card/i... is a perfect example of what you're asking for (for me of course).