Add WebXR Hit Test reference docs - pt 1

[Elchi3]

This talks about Hit testing initialization and adds reference pages for XRSession.requestHitTestSource() and XRSession.requestHitTestSourceForTransientInput().

Spec: https://immersive-web.github.io/hit-test

[github-actions]

Preview URLs

• https://pr8042.content.dev.mdn.mozit.cloud/en-US/docs/Web/API/XRSystem/requestSession
• https://pr8042.content.dev.mdn.mozit.cloud/en-US/docs/Web/API/XRSession
• https://pr8042.content.dev.mdn.mozit.cloud/en-US/docs/Web/API/XRSession/requestHitTestSource
• https://pr8042.content.dev.mdn.mozit.cloud/en-US/docs/Web/API/XRSession/requestHitTestSourceForTransientInput

Flaws

Note! 1 document with no flaws that don't need to be listed. 🎉

URL: /en-US/docs/Web/API/XRSession
Title: XRSession
on GitHub
Flaw count: 2

• macros:
  • /en-US/docs/Web/API/XRHitTestSource does not exist
  • /en-US/docs/Web/API/XRTransientInputHitTestSource does not exist

---

URL: /en-US/docs/Web/API/XRSession/requestHitTestSource
Title: XRSession.requestHitTestSource()
on GitHub
Flaw count: 5

• macros:
  • /en-US/docs/Web/API/XRHitTestSource does not exist
  • /en-US/docs/Web/API/XRFrame/getHitTestResults does not exist
  • /en-US/docs/Web/API/XRRay does not exist
  • /en-US/docs/Web/API/XRHitTestSource does not exist
  • /en-US/docs/Web/API/XRFrame/getHitTestResults does not exist

---

URL: /en-US/docs/Web/API/XRSession/requestHitTestSourceForTransientInput
Title: XRSession.requestHitTestSourceForTransientInput()
on GitHub
Flaw count: 5

• macros:
  • /en-US/docs/Web/API/XRTransientInputHitTestSource does not exist
  • /en-US/docs/Web/API/XRFrame/getHitTestResultsForTransientInput does not exist
  • /en-US/docs/Web/API/XRRay does not exist
  • /en-US/docs/Web/API/XRTransientInputHitTestSource does not exist
  • /en-US/docs/Web/API/XRFrame/getHitTestResultsForTransientInput does not exist

External URLs

URL: /en-US/docs/Web/API/XRSystem/requestSession
Title: XRSystem: requestSession()
on GitHub

No new external URLs

---

URL: /en-US/docs/Web/API/XRSession
Title: XRSession
on GitHub

No new external URLs

---

URL: /en-US/docs/Web/API/XRSession/requestHitTestSource
Title: XRSession.requestHitTestSource()
on GitHub

No new external URLs

---

URL: /en-US/docs/Web/API/XRSession/requestHitTestSourceForTransientInput
Title: XRSession.requestHitTestSourceForTransientInput()
on GitHub

No new external URLs

(this comment was updated 2021-08-19 10:31:58.336392)

[jpmedley]

Nice work. This is clean of typos. I have a few suggestions for wording.

[jpmedley]

What are characteristic points?

The subtext of this question is, if I were a developer who didin't know what this is, would this provide me with enough information find out.

[Elchi3]

hm, yeah, I think this is rather vague and "characteristic points" is what the spec says. Not sure what else to say, though. I believe plane detection and detection using meshes are known concepts to XR/3D developers. For points, this issue argues that point detection could be subsumed into mesh detection: immersive-web/hit-test#66
I'm not expert enough to clarify "points" further. Does it refer to some new detection technique? LIDAR points? Something else? I guess this could be very device-specific also, so maybe that's why the spec left it as such?

Also, the whole entityTypes thing is rather unstable still. See immersive-web/hit-test#67 where some people also recognized that this API is rather hard to grok.

[Elchi3]

At least I've removed entityTypes from the code example now (it is optional anyway).

[jpmedley]

I've requested a definition. I'm fine with resolving this for now.

[Elchi3]

Thanks for your detailed reviews! \o/