That's a two-part project; obviously you'll need to do the RFID on another microcontroller (Arduino, RPi, or other) and pass the data on to the L3D cube's photon micro for it to render the graphics into the WS2812 LED strips.
I won't comment specifically on the RFID part, as this will depend on your choice of microcontroller; at this time I'll focus more on the L3D cube part. But to give you just one example: for the Arduino you'll find numerous examples on implementing an RFID reader; even a practical project such as this can greatly step you up towards building a solution that fits your idea.
As it is, you can render graphics streamed to the cube from a desktop PC. More on this can be learned in this topic, so I won't go into detail here. Basically, there's two ways you can accomplish that:
- Implemented in the beta-cube-library, there's a function (
void Cube::listen()) that allows the cube to listen to data sent to it in UDP packets and render that as color data;
- Based on the above function, I've implemented a similar listener in my Spark Pixels viz; by flashing this viz into the L3D cube and activating the LISTENER mode you will be able to steer graphics to the cube from a desktop PC application (see the topic referenced above for details). My listener is implemented to support TPM2.net, which is a subset of the same UDP protocol, tailored for driving moving LED signs of all sizes. In order to get it working with the L3D cube, you'll have to set up the aforementioned desktop PC application in such a way that it "knows" it'll support an 8x8 LED Matrix over a LAN connection.
Although in both cases the graphics are likely going to look like "moving" pictures, ultimately it's just data being streamed to a photon that's programmed to "listen / decode / display" this data as colors as each completed frame arrives. Same rules apply if you want to display a static graphic. There's no difference. If no data is streamed after a successfully-rendered frame, you'll end up with a cube displaying a static graphic. That being said, all that is left for you to do is to implement a TPM2.net client on the Arduino side, that takes the data from your RFID and streams it to the cube's IP address over a wireless LAN connection.