It seems that Mipmap Filtering and Anisotropic Filtering are not working when an object’s texture is box mapped. They do still work when the mapping is set to planar however.
I tried this with several different image files of varying size with the same result.
Rhino 6 SR11 2018-12-14 (Rhino 6, 6.11.18348.17061, Git hash:master @ 600b621e607cf5226a968db60d7ac9230541b94d)
Licence type: Commercial, build 2018-12-14
License details: LAN Zoo Network Node
Windows 10.0 SR0.0 or greater (Physical RAM: 32Gb)
Machine name: SEA-L17-9T6LNC2
Quadro M2000M/PCIe/SSE2 (OpenGL ver:4.6.0 NVIDIA 391.74)
OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
Redraw scene when viewports are exposed: On
Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: Height
Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 6-4-2018
Driver Version: 23.21.13.9174
Maximum Texture size: 16384 x 16384
Z-Buffer depth: 24 bits
Maximum Viewport size: 16384 x 16384
Total Video Memory: 4 GB
Rhino plugins
C:\Program Files\Rhino 6\Plug-ins\Commands.rhp “Commands” 6.11.18348.17061
C:\Program Files\Rhino 6\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 6\Plug-ins\RhinoRender.rhp “Rhino Render”
C:\Program Files\Rhino 6\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 6.11.18348.17061
C:\Program Files\Rhino 6\Plug-ins\rdk_ui.rhp “Renderer Development Kit UI”
C:\Program Files\Rhino 6\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 6\Plug-ins\RhinoCycles.rhp “RhinoCycles” 6.11.18348.17061
C:\Program Files\Enscape\Bin64\Enscape.Rhino6.Plugin.dll “Enscape.Rhino.Plugin” 2.4.18304.1343
C:\Program Files\Rhino 6\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 6.11.18348.17061
C:\Program Files\Rhino 6\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 6\Plug-ins\Displacement.rhp “Displacement”