3D view of models does not work correctly using relative paths in the footprint when 3D search paths is set

Description

On Windows and Linux When displaying 3d models using a relative path in the footprint and having the "Configure Paths" dialog with a valid 3D search path set, the model is only displayed only once. This happens in both the footprint 3d view and the pcbnew 3d view. Returning to the "Configure Paths" dialog shows the previous setting, pressing "OK" and the footprint 3d view and pcbnew 3d view show the model one time more. Any change to the netlist or component positions will trigger a redraw in the 3d window and the relative path derived 3d models will vanish again, requiring opening of the “configure paths” dialog to restore them.

The setting is being saved as it remembers the path between restarts.

This bug happens in Linux 5.1.5-1.fc31 and Windows 5.1.5-3

Steps to reproduce

In PCBNew open the 3d view of a board that contains 3d model(s) from a search path using a relative path.

1

3d object of J2 is missing

2

Open configure paths dialog and click ok without editing anything

3

Model now appears!

4

Click reload or close/open the 3d view and the model has now vanished

KiCad Version

Linux computer is running;

Application: ModEdit
Version: 5.1.5-1.fc31, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.66.0 OpenSSL/1.1.1d-fips zlib/1.2.11 brotli/1.0.7 libidn2/2.3.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0
Platform: Linux 5.4.18-200.fc31.x86_64 x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
    Boost: 1.69.0
    OpenCASCADE Technology: 7.4.0
    Curl: 7.66.0
    Compiler: GCC 9.2.1 with C++ ABI 1013

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

Windows computer is running;

Application: KiCad
Version: (5.1.5)-3, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.66.0 OpenSSL/1.1.1d (Schannel) zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.1.1) nghttp2/1.39.2
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: 1.71.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.66.0
    Compiler: GCC 9.2.0 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
Edited by Michael Kavanagh