With the release of Unity 4.3, built in support for 2D sprites was added. This makes it easy to import, animate, and render sprites. Unfortunetely, by default the Unity sprite renderer does not support lighting. This means that putting lights in your scene will not have any affect on the rendered image. Luckily, this behaviour is easy to correct on a per-sprite basis.

I’ve started with a blank project and imported the 2D/Sprites folder from the Standard Assets in the asset store. I then placed a few instances of the prototype_green_2x2 sprite and a point light in the middle of the scene, and you can see that there is no lighting applied to the sprites.

To get lighting to working on sprites, it’s just a matter of creating a material and changing its shader to Sprites/Diffuse in the shader dropdown in the inspector. You can now drag and drop the new material into the material section of the Sprite Renderer component of any sprite you want to be affected by lighting. Also, ensure that your light is in front of any sprites that should be affected by lighting. In the example below, the blocks on the right have the new lit material, while the blocks on the left do not.

I hope you found this short post helpful. If you have any further questions please feel free to message me on Twitter @RyanNielson or comment on this post’s page.