generateSphere static method

Future<Mesh> generateSphere({ num radius = 0.5, int latSegments = 32, int lonSegments = 64, String? texturePath, })

Implementation

static Future<Mesh> generateSphere({
  num radius = 0.5,
  int latSegments = 32,
  int lonSegments = 64,
  String? texturePath
}) async {
  int count = (latSegments + 1) * (lonSegments + 1);
  List<Vector3> vertices = List<Vector3>.filled(count, Vector3.zero());
  List<Offset> texcoords = List<Offset>.filled(count, Offset.zero);
  //List<Polygon> indices = List<Polygon>.filled(latSegments * lonSegments * 2, Polygon([0, 0, 0]));

  int i = 0;
  for (int y = 0; y <= latSegments; ++y) {
    final double v = y / latSegments;
    final double sv = math.sin(v * math.pi);
    final double cv = math.cos(v * math.pi);
    for (int x = 0; x <= lonSegments; ++x) {
      final double u = x / lonSegments;
      vertices[i] = Vector3(radius * math.cos(u * math.pi * 2.0) * sv, radius * cv, radius * math.sin(u * math.pi * 2.0) * sv);
      texcoords[i] = Offset(1.0 - u, 1.0 - v);
      i++;
    }
  }

  i = 0;
  // for (int y = 0; y < latSegments; ++y) {
  //   final int base1 = (lonSegments + 1) * y;
  //   final int base2 = (lonSegments + 1) * (y + 1);
  //   // for (int x = 0; x < lonSegments; ++x) {
  //   //   indices[i++] = Polygon([base1 + x, base1 + x + 1, base2 + x]);
  //   //   indices[i++] = Polygon([base1 + x + 1, base2 + x + 1, base2 + x]);
  //   // }
  // }
  Mesh mesh;
  if(texturePath != null){
    ui.Image texture = await loadImageFromAsset(texturePath);
    mesh = Mesh(
      vertices: vertices,
      texcoords: texcoords,
      //indices: indices,
      texture: texture,
      texturePath: texturePath
    );
  }
  else{
    mesh = Mesh(
      vertices: vertices,
      //indices: indices,
    );
  }
  return mesh;
}