IM files

IM Files are the mesh files that display all solid objects in Trainz.

Indexed Mesh files were developed N3V Games as part of the Auran Jet gaming engine that is used in the Trainz Simulators.

The IM file contains all of the geometric and texture mapping data needed to render a solid object.

Any surface or solid object can be rendered as a series of triangular facets. The IM file stores the 3d x,y,z coordinates of the three vertices defining each of the facets as well as the texture mapping data to allow the object to be displayed with the correct surface colours. The separate texture images are referenced by the mesh to connect the image to the appropriate surfaces.

Indexed Meshes are generated by the exporter plug-ins provided by N3V Games for '3DSMax'. The content creator builds the model in 3DSMax and exports the IM file for use in Trainz.

Models can also be built in the the free 3D Blender application. See HowTo/Export from Blender for the export process. N3V's 'TrainzMeshImporter' is used, in this case, to create the IM file from an intermediate XML file.

The exporters can be obtained from the downloads page of this Wiki.

N3V Games provides no editing or manipulation programs for Indexed Meshes, and third party progammers are requested not to alter mesh files. If any changes are needed, the mesh creator must do it...

There is no need for the Trainz user to know the workings of the IM file, so no further data is provided here.