T3D files exist as 3 different types. Please find information about each of them below.
Type 1: Unreal Engine 3D Object File
There can be multiple reasons why you have issues opening T3D files. The good news is that common problems with these Unreal Engine 3D model files are easy to fix. Follow this guide to troubleshoot:
...
There can be multiple reasons why you have issues opening T3D files. The good news is that common problems with these Unreal Engine 3D model files are easy to fix. Follow this guide to troubleshoot:
Install software that can open T3D files. The main reason T3D files won’t open is missing software. Download Unreal Tournament to handle these files.
T3D files store 3D map object data for Unreal Engine games. The text describes items in Unreal maps. Different Unreal Engine versions use different T3D formats.
If installed software won’t open T3D files, right click the file. Open with another program that supports T3D. Check the box to always use that program. This sets the default software for T3D files.
T3D files are used in Windows, Mac and Linux. They are not very common. Unreal Tournament and UnrealEd can view T3D files. The files are exported from UnrealEd.