A special tool helps this mod to make this thing happen. The tool is a kind of the block mixer that basically crushes these two blocks and blends their textures together. During the mixing process, using different kinds of items can give the textures a special effect. For example, the ender pearl can be used to display the nether portal animation on your block.

Detail and Download here : MalisisBlocks Mod

See also : Minecraft 1.7.10 Mods