3d viewer: orthographic view does not render board body at some angles

[Rob Hailman]

When viewing a board in 3d viewer, with both orthographic mode and raytracing enabled, the board body (and things on it - copper, solder mask, silk screen) aren’t rendered when viewing at certain angles. See attached screenshot.

OpenGL mode doesn’t have that problem with the same board.

This seems to happen with every board I throw at it, even ones that worked fine in KiCad 5.0.x.

It’s specific to orthographic mode - if I switch to perspective mode it renders fine. It’s also specific to certain view angles. From the preset views, top, bottom, and front have the issue, while left, right, and back do not.

My suspicion is that it occurs when the rotation on two of the 3 axes is 0, but I haven’t dug deeply enough to confirm that.

KicCad version info:

Application: kicad
Version: (5.1.2)-1, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.61.1 OpenSSL/1.1.1 (WinSSL) zlib/1.2.11 brotli/1.0.6 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.5) nghttp2/1.34.0
Platform: Windows 8 (build 9200), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8)
    Boost: 1.68.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.61.1
    Compiler: GCC 8.2.0 with C++ ABI 1013

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=OFF
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

[Rob Hailman (rjhelms)]

Attached is the project that was used to create the screenshot attached above.

[Mario Luzeiro (mrluzeiro)]

Here is a quick fix for this bug.

[Wayne Stambaugh (stambaughw)]

@Mario, JP merged your patch into the master branch and I cherry-picked it into the 5.1 branch. I modified the commit message so that the KiCad janitor would automatically close the bug report. Thank you for the quick fix!

[Michael Kavanagh (michaelkavanagh)]

master: b9a17b928a288dea9753598914c0fc171b8d4484
5.1: 1dab468e20724a9705c94267d8e57d486c49e63c