Cursor disappears unexpectically in VR mode when looking parallel to the ground

[mattrei]

Description:

• A-Frame Version: master (0.8.0) since build a64773b
• Platform / Device: mobile browsers
• Reproducible Code Snippet or URL: https://aframe-cursor-test.glitch.me

The current a-frame master has a problem with the cursor in VR mode: The cursor ring disappears at about 70 degrees when the HMD is rotating from the ground (negative y-axis) towards the negative z-axis (horizont) and stays invisible. It just appears when looking down again.

The problem arises since this commit.

[mattrei]

is fixed in the latest master commit 8756072