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How X-Plane Builds the World: Meshes, Orthos, and Autogen Explained

X-Plane is known for its realistic landscapes that immerse users in a living world while flying. Three central building blocks make up the scenery: Meshes, Orthos, and Autogen. This chapter explains what these terms mean and how they work together to create the impressive landscapes in X-Plane.

Meshes: The 3D Framework of the World

The X-Plane world can be imagined as a giant 3D puzzle. It all starts with the Mesh. A mesh is the basic shape of the landscape – the digital framework that defines heights and forms of the terrain. It determines how mountains, valleys, hills, or plains look.

  • What is a Mesh? It consists of many small triangles (polygons) that together form a network – hence the name "Mesh" (English for network). These triangles define for X-Plane how high or low a point is and how steep a slope should be.
  • Example: A mountain in X-Plane is defined by a mesh that describes its height, shape, and inclination. Without a mesh, the world would just be a flat plane.

The mesh is thus the first step: It gives the landscape its structure, but no colors or details yet.

Orthos: The Satellite Images for Realism

The second building block is Orthos. While the mesh provides the shape, orthos provide the visual surface – like a giant photo glued onto the mesh.

  • What are Orthos? Orthos are aerial or satellite images that show the earth from above. They contain details like houses, roads, forests, fields, or rivers. In X-Plane, they are placed as image files (e.g., .jpg or .png) on the mesh.
  • Why are they important? Without orthos, the mesh would only look like gray, lifeless hills. Orthos bring the colors and patterns of the real world into play.
  • Example: When flying over a city, thanks to orthos, one can see roofs, streets, and green spaces that look realistic.

Tools like Ortho4XP help download high-resolution ortho images and integrate them into X-Plane. This makes the scenery even more detailed.

Autogen: The World Comes to Life

Mesh and orthos already create an impressive base, but something is still missing: depth. This is where Autogen comes into play. Autogen (short for "automatically generated") adds 3D objects to the landscape that make it come alive – like houses, trees, cars, or power poles.

  • What is Autogen? X-Plane analyzes the landscape (mesh and ortho) and automatically places appropriate objects. It often uses data sources like OpenStreetMap to know where cities, forests, or roads are.
  • How does it work? Autogen "reads" the scenery and distributes objects: trees in forest areas, houses in residential areas, factories in industrial zones. These objects come from libraries provided by X-Plane or add-ons.
  • Example: In a village, thanks to autogen, one can see houses with gardens, trees along the roadside, and maybe a few parked cars. Without autogen, the landscape would be flat – just a satellite image without depth.

Interaction: How Everything Comes Together

The three building blocks work hand in hand:

  1. Mesh: Provides the 3D shape of the landscape, e.g., the height of a mountain or the depth of a valley.
  2. Ortho: Delivers the realistic image that is placed on the mesh, e.g., forests or roads on the mountain.
  3. Autogen: Adds the 3D objects, e.g., trees and houses that perfectly match the scenery.

The result is a world that not only looks real but feels real. When flying over a valley, the mesh forms the hills, the ortho shows green meadows and paths, and autogen scatters cows, trees, and small huts – and there one has the living scenery!

Add-ons and the Next Level

Many X-Plane fans use add-ons to improve meshes, orthos, and autogen:

  • Ortho4XP: Downloads high-resolution satellite images and adapts them to meshes.
  • Ortho Streaming: Solutions like AutoOrtho, XEarthLayer, or XPME stream satellite imagery in real time from the internet — no pre-generation needed, instantly flyable worldwide.
  • Custom Sceneries: Bring better meshes or regional autogen objects, e.g., typical half-timbered houses for Germany.
  • Autogen Libraries: Expand the selection of objects to make the scenery even more realistic.

With such tools, the X-Plane world can be shaped in even more detail – perfect for everyone who wants to dive deep into scenery design.

The Correct Order in scenery_packs.ini: Mesh, Orthos, Autogen, and More

The landscapes in X-Plane are created through the interaction of various components: meshes, orthos, autogen, and special sceneries like airports. For everything to be displayed correctly, the order in the scenery_packs.ini file is crucial. This chapter explains how the order should be structured, why it's important, and how to avoid errors.

The Correct Order of Components

X-Plane loads sceneries from bottom to top in the scenery_packs.ini. This means: entries further down have higher priority and can overwrite entries further up. Based on the main components, the following order results (from bottom to top):

  1. Mesh Files (e.g., HD Mesh, UHD Mesh)

    • Function: Meshes form the 3D basic structure of the landscape, i.e., heights, valleys, and hills.
    • Why first? They are the basis for everything else. Without a mesh, orthos and objects cannot be placed correctly.
    • Example: FlyTampa_Athens_3_mesh or SFD_EDDM_Munich_2_Mesh.

  2. Ortho Sceneries

    • Function: Orthos are satellite or aerial images that are placed on the mesh to represent realistic textures like roads or forests.
    • Why after? Orthos need the mesh to be correctly "stretched," but must be loaded before autogen so objects can be placed on them.
    • Example: z_ortho_California or zz_Ortho_SpainUHDv2_1.

  3. Autogen Objects and Libraries

    • Function: Autogen adds 3D objects like buildings, trees, or vehicles that make the landscape come alive.
    • Why after? Autogen is based on mesh and ortho to place objects correctly (e.g., houses on level ground, no trees on roads).
    • Example: simHeaven_X-World_Europe-6-scenery or simHeaven_X-World_Europe-7-forests.

  4. Special Objects and Masts

    • Function: Special objects like radio masts, wind turbines, or other prominent structures.
    • Why after? These objects should be above autogen to ensure they are visible.
    • Example: Usa_Radio_Masts_01 or world_wind_turbines.

  5. Global Airports

    • Function: Contains the standard airports of X-Plane.
    • Why after? Must be above autogen and orthos, but below custom sceneries.
    • Example: *GLOBAL_AIRPORTS*.

  6. Custom Sceneries and Landmarks

    • Function: Special sceneries like airports or landmarks (e.g., the Eiffel Tower) contain detailed objects and textures.
    • Why at the top? They have the highest priority so they are not covered by other components.
    • Example: Aerosoft_EDDF_Frankfurt_3_Scenery or X-Plane Landmarks - Paris.

Example of a Correct Order

Here is an excerpt from a typical scenery_packs.ini (from top to bottom, i.e., in the order X-Plane loads them):

# Custom Airports and Landmarks (highest priority)
SCENERY_PACK Custom Scenery/Aerosoft-EGLL Airport London-Heathrow_1_DefaultStreets/
SCENERY_PACK Custom Scenery/Aerosoft-EGLL Airport London-Heathrow_2/
SCENERY_PACK Custom Scenery/Aerosoft_EDDF_Frankfurt_1_Parked_Cars/
SCENERY_PACK Custom Scenery/Aerosoft_EDDF_Frankfurt_2_Roads/
SCENERY_PACK Custom Scenery/Aerosoft_EDDF_Frankfurt_3_Scenery/
SCENERY_PACK Custom Scenery/X-Plane Landmarks - Berlin and Frankfurt/
SCENERY_PACK Custom Scenery/X-Plane Landmarks - London/
SCENERY_PACK Custom Scenery/X-Plane Landmarks - Paris/

# Global Airports (standard airports)
SCENERY_PACK *GLOBAL_AIRPORTS*

# Special Objects and Masts
SCENERY_PACK Custom Scenery/Usa_Radio_Masts_01/
SCENERY_PACK Custom Scenery/Usa_TV_Masts_0/
SCENERY_PACK Custom Scenery/world_wind_turbines/

# SimHeaven X-World (Autogen)
SCENERY_PACK Custom Scenery/simHeaven_X-World_Europe-1-vfr/
SCENERY_PACK Custom Scenery/simHeaven_X-World_Europe-2-regions/
SCENERY_PACK Custom Scenery/simHeaven_X-World_Europe-3-details/
SCENERY_PACK Custom Scenery/simHeaven_X-World_Europe-4-extras/
SCENERY_PACK Custom Scenery/simHeaven_X-World_Europe-5-footprints/
SCENERY_PACK Custom Scenery/simHeaven_X-World_Europe-6-scenery/
SCENERY_PACK Custom Scenery/simHeaven_X-World_Europe-7-forests/
SCENERY_PACK Custom Scenery/simHeaven_X-World_Europe-8-network/

# Ortho Sceneries
SCENERY_PACK Custom Scenery/z_ortho_California/
SCENERY_PACK Custom Scenery/z_ortho_Colorado/
SCENERY_PACK Custom Scenery/z_ortho_Florida/
SCENERY_PACK Custom Scenery/zz_Ortho_Alps_West/
SCENERY_PACK Custom Scenery/zz_Ortho_SpainUHDv2_1/

# Mesh Files (lowest priority)
SCENERY_PACK Custom Scenery/FlyTampa_Athens_3_mesh/
SCENERY_PACK Custom Scenery/FlyTampa_Amsterdam_4_mesh/
SCENERY_PACK Custom Scenery/KDEN-Denver International Airport_Mesh/
SCENERY_PACK Custom Scenery/SFD_EDDM_Munich_2_Mesh/

The Special Role of Global Airports

The line SCENERY_PACK *GLOBAL_AIRPORTS* deserves special attention:

  • Position: It should be after custom sceneries and landmarks, but before SimHeaven components and orthos.
  • Function: Global Airports contains the standard airports of X-Plane, often created by the community through the X-Plane Gateway.
  • Why this position?
    • Custom Sceneries (e.g., a detailed EDDF or EGLL) can override the standard airports if they are higher in the list.
    • Global Airports must be above SimHeaven components to ensure airports are not covered by autogen objects.
    • At the same time, Global Airports must be above orthos and meshes so airports are correctly placed on the landscape.
  • Important Note: An incorrect position can lead to problems like "floating" airports, missing taxiways, or covered details.

Why the Order is So Important

The correct order in the scenery_packs.ini is crucial for several reasons:

  • Overlay: Entries further up (with higher priority) overwrite entries further down. An incorrectly placed entry can, for example, make an airport invisible or cover orthos.
  • Correctness: Only the right order ensures that objects are placed correctly – houses stand on the ground, not in the air, and airports fit the mesh.
  • Performance: A logical order helps X-Plane load sceneries more efficiently, which can improve loading times and performance.

Tips for Maintaining the scenery_packs.ini

To ensure sceneries are always displayed correctly, here are some practical tips:

  • Use Tools: Programs like XOrganizer can automatically optimize the order and detect conflicts.
  • Create Backup: Before changing the scenery_packs.ini, a backup copy should be created to be able to undo errors.
  • Test: After changes, a scenery should be loaded in X-Plane and checked to see if airports, orthos, and autogen are displayed correctly. Special attention should be paid to "floating" objects or missing details.
  • Watch for Updates: New sceneries or add-ons can disrupt the order. The file should be checked regularly, especially after installations.