I agree, world scaling is a good thing. Just installed Automobilista 2 and the first thing i noticed was that the car seemed awfully small. In PCars2 and ACC2 I would look at my elbow and my shoulders while wearing the headset and make my scale adjustments from there. You could sense when the scale was right, hand and elbows appear where the should in respect to reality. I feel as though I could reach out toward the other side of the car. I would fine tune to my liking, minor tweaks and all, but usually ended up with a much larger car than in Automobilista 2. I find it much easier to place a car, it just feels a bit more real. And yes, I do find myself looking at my watch, only to realize my in game hand doesn't have one.
This is super important to me, I had to run with about a 30% boost in world scale on PC2 to get it to render properly for me and it's such a big help for immersion - to the extent that I basically didn't play other sims that I knew/felt were better just because VR immersion was so much better in PC2 This and better/directional engine audio would be huge improvements - though I recognise VR is a small niche for a huge studio let alone Reiza.
Yes, edit the Documents\Automobilista 2\openvrsettings.xml, and change the following line: <prop name="IPD_Scale" data="0.766269" /> This is equivalent to a 130% world scale (1 / 0.766), and needed because I use VROptician lens inserts with a -5.25 diopter (sphere). A negative lens shrinks the world scale you see, the further away from your eyes it sits, while the opposite is true for a positive diopter (reading glasses / magnifying glass). With my contact lenses on, I only need 105% world scale since they sit very close.
I could've sworn World Scale was added to the UI but I can't seem to find it must be thinking of another Sim
There has never been a World Scale setting in the UI, from what I can remember. Only the XML file setting as described by Lexx VR above. In other news, the v1.17.8 beta for Steam VR now has a World Scale setting (source)
The new beta of steamvr has game independent fov and world scale sliders now. Make sure you are on beta then go to settings, video, specific game settings you will see it there. SteamVR Update Adds Clarity-boosting Field-of-view Option and World Scale Adjustment edit, Roar above beat me to it.