private void GenerateCubemap()
{
var camera = _camera ? _camera : SceneView.lastActiveSceneView.camera;
var cubemap = _cubemap ? _cubemap : new Cubemap(128, TextureFormat.RGBAHalf, false);
camera.RenderToCubemap(cubemap);
var tex = TextureHelper.ConvertCubemap2Texture2D(cubemap);
// File.WriteAllBytes(EditorUtility.SaveFilePanelInProject("保存 Cubemap", "Cubemap.exr", "exr", ""), tex.EncodeToEXR());
File.WriteAllBytes(EditorUtility.SaveFilePanelInProject("保存 Cubemap", "Cubemap.png", "png", ""), tex.EncodeToPNG());
}