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2.8 Cycles viewport Ray Visibility is not updated in viewport when changed by Python
Open, Confirmed, MediumPublic

Description

System Information
Operating system: Mac OSX, 10.13.6 (a MacBook Air)
Graphics card: Intel HD Graphics 5000 1536 MB

Also tried on a linux virtual machine (Ubuntu), same issue

Blender Version
Broken:
Mac build: 2.80.43, build 2019-02-01 22:37
Linux build: 2.80., 2019-02-15 7:29
Worked: 2.79, unsure if there was a working version of 2.8

Short description of error
When updating an object's CyclesRay visibility (e.g. camera visibility) via python from a script or console, there is no impact in the viewport; while the UI as well as render will reflect the changed state of the setting (checking or unchecking the box), the visibility will not have changed in the viewport. Note: this is only an issue for the viewport, when rendering it will reflect the setting update properly. The issue persists even between leaving and re-entering rendered mode in the viewport, until the user manually clicks to toggle the UI setting directly which resolves the problem.

Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).

  1. Open default scene
  2. Open console window/scripting workflow,
  3. Enable cycles and enter a viewport into rendered mode
  4. With Default cube selected, type: C.object.cycles_visibility.camera = false
  5. Notice how viewport scene does not update; but if you move the mouse over the property panel:Objects/Cycles settings, you'll see the draw refresh will show the camera visibility turns off
  6. Exit and re-enter rendered mode in the viewport, to find the issue persists (cube is visible to camera)
  7. Press render to notice that the setting however is reflect in render (cube will not be visible to camera)
  8. Manually toggle the camera visibility setting in by clicking the tick box twice, to verify the setting works when done by hand; and see that now the cube does not appear in the viewport (as expected).
  9. Repeat for reverse; ie turning setting to True when initial camera visibility is false.

Note I also tested this and found the same issue with the Glossy visibility using a similar process (adding a mirror-like object next to the cube), so I expect this is true for all of the cycles object visibility settings.

Video demonstration, happens in any scene including the default
https://drive.google.com/file/d/1RamYXwGauAKGiipCHnIGnqq6saokDmYg/view?usp=sharing

While I agree this is less of an issue since ultimately the correct results appear in render, this is an issue for addons that control this setting and confuse the user as prior to render, there then appears to be a discrepancy between the viewport visibility and the panel settings.