[BUG-234815] [PBR] Reflection Probes (when using multiple) cause different reflections

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What just happened?

1. If you place an item where one part Is touching one cube probe and the other part the adjacent cube probe the reflections will differ. (Probes are part of the link set)
2. Gif attached showing me moving a piece of furniture across two adjacent probes so you can see the effect.
   https://gyazo.com/43c126a15353d9ff4d3b7102395788f8

What were you doing when it happened?

Placing an item where two adjacent probes are situated.
(Dan Linden has a copy of this build if needed for testing)

What were you expecting to happen instead?

1. The probes when placed in a build to fill an interior room (in this test case two probes) should not cause conflicting reflections in this manner.

2. With the two probes in this format it would prohibit users placing furniture or items along the edge of two adjacent probes.

3. I tested using various  ambience and falloff settings.

   Other information

   These are complex probes as this is a L Shaped (sort of) room that is open plan as we can't upload a mesh shape for the probe and have to instead use cubes the only choices to fill this room is two or three probes (in my test I used two). Unless there is a different approach to this?

   Tested at ground level below 64M due to the other bug with probes at height.

   Note Unity had this problem some years back with L Shaped Rooms and now uses blending for probes.  (https://docs.unity3d.com/Manual/UsingReflectionProbes.html#:~:text=Blending,one%20zone%20to%20the%20other)

Original Jira Fields

Field	Value
Issue	BUG-234815
Summary	[PBR] Reflection Probes (when using multiple) cause different reflections
Type	Bug
Priority	Unset
Status	Needs More Info
Resolution	Unresolved
Labels	pbr
Reporter	Charlotte Bartlett (charlotte.bartlett)
Created at	2023-12-10T18:16:39Z
Updated at	2023-12-12T15:07:58Z

{
  'Build Id': 'unset',
  'Business Unit': ['Platform'],
  'Date of First Response': '2023-12-10T13:01:43.184-0600',
  "Is there anything you'd like to add?": "These are complex probes as this is a L Shaped (sort of) room that is open plan as we can't upload a mesh shape for the probe and have to instead use cubes the only choices to fill this room is two or three probes (in my test I used two).     Unless there is a different approach to this? \r\n\r\nTested at ground level below 64M due to the other bug with probes at height.",
  'ReOpened Count': 0.0,
  'Severity': 'Unset',
  'System': 'SL Viewer',
  'Target Viewer Version': 'viewer-development',
  'What just happened?': '1. If you place an item where one part Is touching one probe and the other part the adjacent probe the reflections will differ. (Probes are part of the link set)\r\n2. Gif attached showing me moving a piece of furniture across two adjacent probes so you can see the effect.\r\nhttps://gyazo.com/43c126a15353d9ff4d3b7102395788f8\r\n',
  'What were you doing when it happened?': 'Placing an item where two adjacent probes are situated.\r\n(Dan Linden has a copy of this build if needed for testing)',
  'What were you expecting to happen instead?': '1. The probes when placed in a build to fill an interior room (in this test case two probes) should not cause conflicting reflections in this manner.\r\n2. With the two probes in this format it would prohibit users placing furniture or items along the edge of two adjacent probes.',
}

[sl-service-account]

1hannah.actor commented at 2023-12-10T19:01:43Z

This issue is specifically regarding the blending between Box probes - sphere probes are already blended.

[sl-service-account]

Charlotte Bartlett commented at 2023-12-11T03:31:05Z

I did some further testing tonight and found that if the L Shape is significantly overlapped - blend seems to be ok in that scenario.  

I need to test more, but if that is "working" then the wiki docs should have a few lines to let people know to ensure there is an overlap needed with box probes for blend to kick in for an L shape (I used 50%).  Versus having the box probes just abut each other.

Updated Probes (so far working) - https://gyazo.com/1f2ead424cb72214b4c1709a56c84fcf

Original Probes (issue above with the chair as shown) - https://gyazo.com/9757b3800e33a8021731844935c4a546

[sl-service-account]

JIRAUSER341268 commented at 2023-12-12T15:07:48Z

Thanks for the report Charlotte!

This is currently a known issue but as Jenna has mentioned above, this only occurs for box probes. 

This issue has now been linked to an internal Jira we have for this.

I'm leaving this Jira set to 'Needs More Info' for now in case you'd like to report more findings with further testing.