This guide shows you how to convert a Marathon map to Garry’s mod.

### The start

This guide will show you how to convert a Marathon map to Garry’s mod. You will need a Marathon map editor named Weland and the hammer editor for Garry’s mod.

### The basics

Marathon’s map size can be measured in world units, one unit is 1024. We need to convert this to 128 world units. With all the test maps I made in Garry’s mod 128 seems to be the best size and the 1/8 grid matches hammer editor 16×16 unit grid.

We will start with this simple polygon in Weland. It has four vertices with a floor and a ceiling.

Double click a vertex and it will give you the X and Y coordinates. We need to convert the X coordinate and then the Y coordinate.

X coordinate is -2048.

Now 2048 is divided by 1024 and multiplied by 128 equals 256.

2048 / 1024 * 128 = 256

The X coordinate is still negative on the grid so X is -256.

The Y coordinate is 0 so we don’t have to use math.

Convert the other 3 vertices to Garry’s mod size.

In the hammer editor use the 16 grid size and use the top view. The lower right contains the @ location for X and Y the mouse is pointed at on the top view grid.

Locate X:-256 and Y:0 on the top view grid and use the block tool to make a brush with the other 3 vertices XY information.

The brush should be 256 x 256 x 16.

Now select the polygon in Weland to check the floor and ceiling heights.

Floor height is 0 and ceiling height is 1.000 in the lower left of weland next to polygon index.

### The floor

If its not then use the selection tool and move the brush until the top of it is at 0 Z coordinate.

The brush top @ Z coordinate 0 is the floor.

### The ceiling

Multiply 1 times 128 and it equals 128.

1 * 128 = 128

The ceiling is 128 Z coordinate.

In the hammer editor use the selection tool and select the brush wile holding down shift on the keyboard and move it up. The brush has now been cloned.

Now move the brush up until the bottom of it is on 128 Z coordinate.

The brush bottom @ Z coordinate 128 is the ceiling.

### The walls

Do this for all the sides in the top view and seal the map.

Now you know how to convert a Marathon map to Garry’s mod.