Spotlamp with buffer shadow + object without "Cast buffer shadow" = artifact #34895

New Issue

William Chargin · 2013-04-06T04:15:24+02:00

William Chargin commented

2013-04-06 04:15:24 +02:00

%%%--- Operating System, Graphics card ---
MacOSX 10.8.2 (12C60), 2.26 GHz Intel Core 2 Duo, 4 GB 1067 MHz DDR3 RAM, NVIDIA GeForce 9400 256 MB

- Blender version with error, and version that worked ---

2.66.0 r54697 has error

- Short description of error ---

A spot lamp with halo and buffer shadow combined with an object that doesn't have "Cast Buffer Shadow" (Material RNA: use_cast_buffer_shadows) has a plus-shaped artifact (possibly a triad) in the render view. Enlarging the value of the spotlight's "Halo Step" value (Lamp RNA: halo_step) enlarges the shadow. Setting spotlamp to "No Shadow" or "Ray Shadow" alleviates issue. Checking "Cast Buffer Shadow" alleviates issue.

- Steps for others to reproduce the error (preferably based on attached .blend file) ---

Open file, F12. You will see a crosshair on the letter "B".
Switch the object's material to "F WithBufferShadow." Press F12. The artifact is gone.
If you want, go to the lamp ("Spotlight") and increase the Step value to get a bigger crosshair.

Also attached: images with and w/o artifact.%%%

%%%--- Operating System, Graphics card --- MacOSX 10.8.2 (12C60), 2.26 GHz Intel Core 2 Duo, 4 GB 1067 MHz DDR3 RAM, NVIDIA GeForce 9400 256 MB - Blender version with error, and version that worked --- 2.66.0 r54697 has error - Short description of error --- A spot lamp with halo and buffer shadow combined with an object that doesn't have "Cast Buffer Shadow" (Material RNA: use_cast_buffer_shadows) has a plus-shaped artifact (possibly a triad) in the render view. Enlarging the value of the spotlight's "Halo Step" value (Lamp RNA: halo_step) enlarges the shadow. Setting spotlamp to "No Shadow" or "Ray Shadow" alleviates issue. Checking "Cast Buffer Shadow" alleviates issue. - Steps for others to reproduce the error (preferably based on attached .blend file) --- Open file, F12. You will see a crosshair on the letter "B". Switch the object's material to "F WithBufferShadow." Press F12. The artifact is gone. If you want, go to the lamp ("Spotlight") and increase the Step value to get a bigger crosshair. Also attached: images with and w/o artifact.%%%

William Chargin commented

2013-04-06 04:15:24 +02:00

Changed status to: 'Open'

Ton Roosendaal commented

2013-04-06 14:55:16 +02:00

%%%Confirmed - this is most likely a floating point precision error, the code tries to intersect the view vector with the lamp cone, and there it exactly looks into the cone tip...%%%

Ton Roosendaal commented

2013-04-18 18:27:02 +02:00

%%%The code that was sampling the shadowbuffer exited too soon (for ray going perpendicular to buffer it should take at least 1 sample).
Fix in svn. Code from 90ies, whoa ;) Thanks!%%%

%%%The code that was sampling the shadowbuffer exited too soon (for ray going perpendicular to buffer it should take at least 1 sample). Fix in svn. Code from 90ies, whoa ;) Thanks!%%%

Ton Roosendaal commented

2013-04-18 18:27:02 +02:00

Changed status from 'Open' to: 'Resolved'

Ton Roosendaal closed this issue

2013-04-18 18:27:02 +02:00

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Spotlamp with buffer shadow + object without "Cast buffer shadow" = artifact #34895