Usually the rolled up bitumen track is continuously rolled out during the welding process by using your left or right foot. Since we didn’t use any additional trackers in the VR training, the unrolling of the virtual bitumen track had to be fully automated.

For this I concepted and implemented several conditions which had to be met by the player to automatically unroll the bitumen. The conditions that the player has to meet are introduced one by one together with visualizations on the ground and specific visualizations pop-up while welding, depending on which condition is not met.

1. head distance
   Part of learning how to weld is getting the feeling of the pace with which you need to weld. I used the head distance to an offset position of the rolled up bitumen and smoothly start rolling the bitumen track with a fixed maximum speed once bending over the rolled up bitumen.

   Since people are different height and need to be able to comfortably look at where they are welding, I balanced the conditions to get a sweet spot that works for most people in the established target group.

2. torch
   As a second condition, to be able to start rolling the rolled up bitumen, the torch, with which you weld the bitumen, has to be activated (pressing a button on the controller). Additionally the torch needs to be close to the rolled up bitumen. This ensures the player is actively trying to weld.
3. direction
   Checking if the player is on the correct side of the rolled up bitumen and facing the correct direction additionally helps to ensure the player is actively trying to weld.

Once the bitumen starts rolling out, there is a short delay before the bitumen track stops rolling. This feels smoother and not as harsh on the player when they’re accidentally not meeting all conditions.