Bug#831991: blender: The glossy shader displays reflections in black sometimes

[Teemu Likonen]

Package: blender
Version: 2.72.b+dfsg0-3
Severity: important

The Cycles rendering engine has "glossy shader" which is for materials'
specular reflections. Sometimes those reflections are completely black.
I'll try to attach a screen shot image and the .blend file. In the
problem situation there's object's option "Shading: smooth" active.

-- System Information:
Debian Release: 8.5
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.6.0-0.bpo.1-amd64 (SMP w/8 CPU cores)
Locale: LANG=fi_FI.UTF-8, LC_CTYPE=fi_FI.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages blender depends on:
ii  blender-data                      2.72.b+dfsg0-3
ii  fonts-droid                       1:4.4.4r2-6
ii  libavcodec56                      6:11.7-1~deb8u1
ii  libavdevice55                     6:11.7-1~deb8u1
ii  libavformat56                     6:11.7-1~deb8u1
ii  libavutil54                       6:11.7-1~deb8u1
ii  libboost-date-time1.55.0          1.55.0+dfsg-3
ii  libboost-filesystem1.55.0         1.55.0+dfsg-3
ii  libboost-locale1.55.0             1.55.0+dfsg-3
ii  libboost-regex1.55.0              1.55.0+dfsg-3
ii  libboost-system1.55.0             1.55.0+dfsg-3
ii  libboost-thread1.55.0             1.55.0+dfsg-3
ii  libc6                             2.19-18+deb8u4
ii  libfftw3-double3                  3.3.4-2
ii  libfreetype6                      2.5.2-3+deb8u1
ii  libgcc1                           1:4.9.2-10
ii  libgl1-mesa-glx [libgl1]          10.3.2-1+deb8u1
ii  libglew1.10                       1.10.0-3
ii  libglu1-mesa [libglu1]            9.0.0-2
ii  libgomp1                          4.9.2-10
ii  libilmbase6                       1.0.1-6.1
ii  libjack-jackd2-0 [libjack-0.116]  1.9.10+20140719git3eb0ae6a~dfsg-2
ii  libjpeg62-turbo                   1:1.3.1-12
ii  libjs-jquery                      1.7.2+dfsg-3.2
ii  libjs-jquery-ui                   1.10.1+dfsg-1
ii  libopenal1                        1:1.15.1-5
ii  libopencolorio1                   1.0.9~dfsg0-3
ii  libopenexr6                       1.6.1-8
ii  libopenimageio1.4                 1.4.14~dfsg0-1
ii  libopenjpeg5                      1:1.5.2-3
ii  libpng12-0                        1.2.50-2+deb8u2
ii  libpython3.4                      3.4.2-1
ii  libsdl1.2debian                   1.2.15-10+b1
ii  libsndfile1                       1.0.25-9.1+deb8u1
ii  libspnav0                         0.2.2-1
ii  libstdc++6                        4.9.2-10
ii  libswscale3                       6:11.7-1~deb8u1
ii  libtiff5                          4.0.3-12.3+deb8u1
ii  libx11-6                          2:1.6.2-3
ii  libxi6                            2:1.7.4-1+b2
ii  libxxf86vm1                       1:1.1.3-1+b1
ii  zlib1g                            1:1.2.8.dfsg-2+b1

blender recommends no packages.

blender suggests no packages.

-- no debconf information
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