====== ArmA 3 Terrain Builder ======

[[https://www.pmctactical.org/forum/viewforum.php?f=68|ArmA 3 Forum]], [[:arma3|ArmA 3]], [[arma3:config|ArmA 3 Config]], [[arma3:missions|ArmA 3 Missions]], [[arma3:modeling|ArmA 3 3D Modeling]], [[arma3:scripting|ArmA 3 Scripting]], [[arma3:terrain|ArmA 3 Terrain]], [[arma3:texturing|ArmA 3 Texturing]], [[arma3:tools|ArmA 3 Tools]]

[[arma3:terrain:terrain-builder|ArmA 3 Terrain Builder]], [[https://www.pmctactical.org/forum/viewtopic.php?f=70&t=23005|ArmA 3 Terrain Builder Support Forum]]


====== Heightmap Resize ======

**Terrain Builder** can be used to **resize** your **heightmap**.

Important note: this method does not "add details" to your heightmap, but your terrain looks smoother because the increased amount of heightmap grid points. If you want you can then add more details to your terrain with your favorite terrain heightmap editor, its just important to realize the details wont appear there by //magic// heh.

Increasing the heightmap grid size but still maintaining compatibility with terrain + objects is tricky, meaning you don't want your objects floating in the air or buried in the ground. Lets say you have 256 x 256 grid heightmap and 50 meter cell size coming to 12.8km terrain, now if you want to increase the heightmap grid and decrease cell size therefore making terrain more detailed and smooth, divide the cell size by two every time you multiply heightmap, like this:

**Heightmap original 256, cell original 50:**
^ Heightmap New ^ Cell New ^
| 512| 25 |
| 1024 | 12.5 |
| 2048 | 6.25 |
| 4096 | 3.125 |

In our 256 example size, if you want to increase heightmap to 1024 you would drop cell size from 50 -> 25 -> 12.5 which would still keep same 12.8km terrain size, objects would remain in their proper location and heightmap would be "transformed" smoothly in place just adding more grid points for details.

**VERY IMPORTANT:** you must export and delete special objects (like bridges, harbor or others which are aligned other than their normal align to ground elevations) with absolute elevations before resizing your heightmap, otherwise these special objects will move along with the heightmap. After you've done the resizing you can import them back into terrain builder using absolute elevation mode.

Normal objects like bushes, rocks, trees etc and normal buildings are fine with this resize using their relative elevation modes in terrain builder and remain on their original place.

HOWTO increase your existing terrains heightmap grid size in terrain builder:
  - mapframe properties -> samplers, edit terrain sampler grid size (heightmap) from 256 to 1024
  - edit cell size from 50 to 12.5 when your texture layer will update automatically but check that its about 4x the cell size anyways
  - import your 256 x 256 grid heightmap .asc even though you already had it imported
  - rebuild terrain from the mapframe properties -> processing tab
  - delete the imported heightmap.asc raster (not necessary but always good thing to do)
  - delete existing layers dir, grid file and generate layers (because heightmap/cell specs have changed)

And you're all done, if you want you can export your terrain back out to ASC file now for backup purposes.