zadinvit / bigpluginmitsuba

Big image group plugin for mitsuba

bigbtf mitsuba plugin This plugin is part of my diploma thesis "Visualization of advanced material appearence representations." plugin allows rendering of BTF textures in MIF format https://github.com/RadomirVavra/MIFlib (The Institute of Information Theory and Automation (UTIA)). Instalation

1. add code to mitsuba/ext/CMakeLists.txt
2. Copy folder bigplugin to mitsuba/src/bsdfs
3. in mitsuba/src/bsdfs edit CMakeLists.txt add a row 3.1. add_plugin(bigbtf bigplugin/bigbtf.cpp)
4. now you need link libraries (you can use MIFlib 0.4 version from this repository (folder MIFlib) or download newer version from https://github.com/RadomirVavra/MIFlib)
5. Use Cmake to generate new Mitsuba.sln, in solution go to folder plugins/bsdfs/bigbtf, there are bigbtf project files 5.1. In bigbtf project you need set path to directories which stores MIFlib and PNGlib (in bigplugin folder). So in Linker->General->Additional Library Directories add the path to MIFlib 5.2 In Linker->Input->Additional Dependencies add "MIFlib.lib;PNGlib.lib" 5.3 In bigbtf-obj project go to properties C/C++->General->Additional Include Directories and add the path to MIFlib\include and path to folder with bigbtf plugin include directory, you can add the path to plugin in mitsuba path_to_mitsuba\mitsuba\src\bsdfs\bigplugin\ext\include
6. Now you can build mitsuba INSTALL project and now you have mitsuba with bigbtf plugin, or you can build only bigbtf plugin and go to build/src/bsdfs/release and copy bigbtf.dll to dist/plugins, this work too and you don't need to reinstall whole Mitsuba

Use To add BTF texture to your object you need to use this tag

<bsdf type="bigbtf" id="basket">
      <string name="filepath" value="F:\vita_skola\mitsubaTestFiles\mifFiles\MAM2014_016.mif"/>
      <boolean name="memory" value="true"/>
      <string name="cubemap_path" value="\cubemaps\081\0256"/>
      <float name="scale" value ="400.0"/>
      <string name="filtering" value="ANIZO_4x"/>
      <integer name="level" value="3" />
    </bsdf>

Only filepath parameter is mandatory, but i recomend use memory tag with true, for load BTF textures to memory while rendering. For UBO reprenzentations of textures you need add path to cubemaps with interpolations indexes. ( <string name="cubemap_path" value="path_to\cubemaps\081\0256"/>) Scale parameteris use to scale size of texture, default value is 7. Plugin support mipmapping and anisotropy filtering, you can use it with parameter filtering, but you need to generate mif files with mipmaps this filtering (you can generate this files with https://github.com/zadinvit/bigConvert)

You can use parameter level to change the default level of filtering, so if you want to start filtering closer to the camera add a positive value.

Types of filtering

• MIPMAP_LINEAR - mipmapping without interpolation between levels
• MIPMAP_WEIGHTED - mipmapping with interpolation between levels
• ANIZO_1x - anisotropy filtering without interpolation between levelx and levely (recommended)
• ANIZO_4x anisotropy filtering with interpolation between levelx and levely (not recommended - slow + same results as ANIZO_1x)
• none

For developers You can use big_render.cpp/.hpp for support rendering BTF texture in mif format inf other renders. You only need implement same logic, which i implement in bigbtf.cpp.

Documentation created by Vít Zadina