- Copy the .osl or .oso file to the $C4D_INSTALL/plugins/C4DtoA/shaders folder. All plugins located in this folder are read automatically by the plug-in. Meta data (.mtd) file placed next to the OSL shader is also loaded. If the shader ships with C4D UI resource files (.res, .h, .str) you have to copy them to the $C4D_INSTALL/plugins/C4DtoA/res folder.
Make sure you have write permission in the folder where the .osl file is located, because Arnold will compile and write the .oso file there.