Google’s (GOOG) upcoming mobile virtual reality platform, due to arrive in the fall, is called Daydream. Its Daydream Labs team wrote Tuesday that its experiments with virtual shopping had shown how people could annoy or upset one another.

For example, people could pick up virtual hats or accessories and, instead of trying them on their virtual selves, they could use them to block the vision of other users, in some cases forcing their victims to restart their shopping experience.

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“People are curious and will test the limits of your VR experience. For example, when some people join a multiplayer app or game, they might wonder if they can reach their hand through another player’s head or stand inside another avatar’s body. Even with good intentions, this can make other people feel unsafe or uncomfortable,” wrote user experience designer Robbie Tilton.

The solution? Designing personal space around each user.

According to Tilton, the Daydream team built an experiment where the users are dogs playing poker. If someone tries to get up from the table, the other players can no longer see them, and there are visual cues to guide them back to their seat.

Here’s what that looks like:

[youtube https://www.youtube.com/watch?v=BoOVVx9CnL8&w=560&h=315]

Meanwhile, in another experiment the designers found users “loved” the positive reinforcement they got when they made friendly contact with others—high fives earned a fireworks animation and a slapping sound. Punching another avatar’s body got nothing.

“If you want people to interact in positive ways…try giving them an incentive,” Tilton wrote.

For more on Google and virtual reality, watch our video.

In a previous post, the team claimed multiplayer virtual-reality activities could make the real world “melt away.”