Bevy_Mesh_Terrain Collider Spawning Example

gistfile1.txt

/*

You can use a system like this in your own code to spawn colliders for the terrain chunks
This example uses bevy xpbd 3d Colliders  

This will loop through all built chunks and replace their ChunkCollisionData component with your own Collider component for whatever physics engine you are using
*/

pub fn build_colliders_for_terrain_chunks(
    mut commands:Commands, 
    mut chunk_query: Query<(Entity,  &mut Chunk, &ChunkCollisionData, &Transform), Without<Collider>> ,
    
 ){
    
    for (chunk_entity, chunk, chunk_collision_data, transform) in chunk_query.iter_mut(){
        
         //should match terrain config 
         let terrain_height_scale_y = 0.004;  
         let terrain_dimension_width = 1024.0 as u32; 
         let chunk_rows = 16; 
         
         
         
        let chunk_width = terrain_dimension_width / chunk_rows; 
         
        let scale = Vec3::new(chunk_width as f32,terrain_height_scale_y, chunk_width as f32);
         
        let subheightmap =  &chunk_collision_data.heightmap;
         
        let heights_raw:&Vec<Vec<u16>> = &subheightmap.height_data;
         
            
        let heights: Vec<Vec<f32>> = heights_raw.iter()
            .map(|row| {
                row.iter()
                    .map(|&val| val as f32)
                    .collect()
            })
            .collect();
            
            
         let collider = Collider::heightfield(
              heights,
              scale
              );  
              
         let initial_position = transform.translation; 
     
         // println!("added chunk collider ");
          //add our built collision heightfield and remove the other component 
          if let Some(mut entity_commands) =  commands.get_entity(chunk_entity){
                
              entity_commands.insert( 
                    collider  
                );
              entity_commands.insert( 
                   RigidBody::Static 
                ) ;
            /*  entity_commands.insert( 
                  Position::from( initial_position ) 
                );*/
              entity_commands.remove::< ChunkCollisionData >(   );
          
          }
         
         
    } 
    
    
}