We were tasked to create a crate with the design of our choice, however the majority of the detail must be baked on using normal maps. I decided to use a standard 6 sided cubed (12 tris) as an experiment to see how much detail I could actually get from just normal map data.
I started with a 1m x 1m x 1m cube, then duplicated it to then use as my base for my high poly version. I decided to follow the design of a TNT crate from the Crash Bandicoot games on Playstation 1 created by Naughty Dog. Using the reference images similar to the above, I was able to come up with the below design.
I then exported both the high and low poly mesh, ready for baking for which I used the Substance Designer software from Allegorithmic. The normal map could be baked with 3DS Max, Maya or even XNormal, however I have had good results using Substance in the past. Also, Substance Designer allows me to combine both average and none average normal maps using a masking technique as shown below.
The combining of normal maps is shown above, with the black section displaying none average normal and the white mask displaying the average normal. The individual and combined normal maps are shown below.
As you can see, the Average Normal provides nice and soft outer edges however skews the detail on the faces. The None Average Normal provides a harsh outer edge and perfect detail on the faces. Therefore combining the two provides the softer outer edge whilst maintaining the precise detail on the faces, which transfers really well with little to no noticeable artifacts. This is also why my UV islands are separated, as I was getting harsh / black edges when stitched together. My final result is shown below.
I am really pleased with my final normal map and was actually quite surprised how much detail / depth I was able to achieve on such a basic mesh. I was intending to stop at just creating the normal map as tasked, however I now intended to continue this project to completion and texture this model in the coming days. I will provide an update in the near future.