Skybox Surround

The initial idea for the skybox was to have it composed of multiple layers to give a slight parallax effect when the player traversed the environment, it worked well when the images were applied but because of the sheer scale of the skybox the parallax was hard to notice.

It also seemed to ramp up processing on the devices I tested, this was due to how materials behave within Unity. I was using a transparent cutout shader on the single skybox mesh, but when the game was run the engine had to render a transparent texture on top of another transparent texture exponentially. Not only was it rendering each layer, but it was having to re-render the back drop 16 times and frame. The skydome was also divided up in to seperate material IDs which allowed me to apply 5 4096x1024 textures (another bad idea!).

I believe there is place for a skydome like this, but not for a mobile game with current technology.

Here is an example of how the multi-tiered dome worked :  

After working on the graphics for the surround I managed to get something that worked well and blended nicely with the foreground elements. Here is a visual progression of the backdrop, I found it helped to bring both foreground objects gently in to the backdrop to help blur the seam and viceversa.

After producing a final backdrop I needed to optimise the skybox itself to run on iOS and Android devices. The most effective way to do this and maintain a good quality texture was to merge the layers together and have a single cylindrical capped skybox. The second problem which arose was iOS devices up to iPad2 can only manage 1024x1024 textures and therefore my 4096x1024 wouldn't work. I got around this problem by dividing the cylinder in to 4 seperate material IDs and dividing the large backdrop texture in to four 1024x1024 textures. This worked perfectly, the only drawback is now editing them takes four times aslong (to ensure they match up, and they are in four different documents).