Import Gaea terrain as a mesh (OBJ/FBX)

1. Create a Geometry container
   • /obj → Tab → Geometry → dive inside.
2. Import the mesh
   • OBJ: add a File SOP and pick the .obj.
   • FBX: use File → Import → Filmbox FBX… (creates a network), then dive to the SOP level.
3. Scale the normalized 0..1 mesh to meters
   • Append Match Size SOP.
   • Turn Scale to Fit ON (this is the node’s scaling feature). (?)
   • Turn Uniform Scale OFF (so you can fit a non-cube: 5000×2500×5000). (?)
   • Set the target Size to:
     • X = 5000
     • Y = 2500
     • Z = 5000
4. Fix orientation if needed
   • Houdini terrains typically live on the ground plane; HeightField tools default to ZX as the "ground" alignment. (?)
   • If your imported mesh is "standing up" or using a different up-axis, add a Transform SOP and rotate until it sits flat.

Import as a Heightfield

1. Create a Geometry container
   • /obj → Tab → Geometry → dive inside.
2. Load the heightmap as a Heightfield
   • Add Heightfield File SOP.
   • Set File to your heightmap (prefer EXR/32-bit+).
3. Set terrain footprint to 5000 m
   • In Size:
     • Size Method = Size of Largest Axis
     • Size = 5000 (meters). (?)
4. Set max altitude to 2500 m
   • In Height:
     • Height Scale = 2500 (this scales the height values from the image). (?) With your convention (black=0, white=ceiling), this makes white map to ~2500 m.
5. (Optional) Confirm alignment
   • HeightField File’s default Orientation is ZX (ground plane). (?)