.ATM File

The atm file extension is related to TerraGen software and used for files that contain data about atmosphere.

Terragen is a program for rendering and animating realistic natural environments and terrains.

Files with atm file extension might also be atmosphere settings for TerraGen environment rendering program.

How to open:

These files are perhaps loaded to the program to change the settings for rendering.

How to convert:

Probably cannot be converted to anything else.