Okay, we have our high-polygon object and our low-polygon object with UV coordinates ready, and we would like to view it in real-time in a game engine. Let's see how we can transfer fine details onto our low-poly drone with normal maps in ZBrush.
So, what we want to do is create a normal map and export it so that we can use it in our engine:
1. Open the latest version of the drone.
2. Step down to the lowest level of subdivision.
3. Make sure that Tool | UV Map | UV Map Size is set to 1024, which are the dimensions of the texture in pixels in width and height.
4. Expand the Tool | Normal Map subpalette.
5. Enable Tangent, Adaptive, and SmoothUV, as the next screenshot shows:
6. Click on the Create NormalMap button — this will incorporate only the visible layers. Check the Notebar to see the generation progressing, as the subsequent screenshot shows:
7. If this takes too long, you can cancel the process by pressing the Esc key. Turning off Adaptive...