getheightatcoordinates anyone having issues with : ground.getHeightAtCoordinates(x, z) when loading many meshes?

[JonathanRev]

Hello good day team from babylon , i am really glad to have known babylon as well, it is a great tool ,

i am currently having some issues when using : ground.getHeightAtCoordinates(x, z) , i am currently using the export Toolkit that exports from Unity to Babylon js .  i have imported the meshes to my scene using the "assetsManager" this way : 

                                                                                     var stones = assetsManager.addMeshTask("stones", "", "assets/stones/", "stones.babylon");

                                                                                     stones.onSuccess = function(task) {

                                                                                            task.loadedMeshes.forEach(function(mesh) {
                                                                                                     mesh.isVisible = false;

                                                                                                     var range = 1024;
                                                                                                     var count = 40;
                                                                                                     for (var index = 0; index < count; index++) {
                                                                                                              var newInstance = mesh.createInstance("j" + index);
                                                                                                              var x = range / 2 - Math.random() * range;
                                                                                                              var z = range / 2 - Math.random() * range;

                                                                                                              var y = ground.getHeightAtCoordinates(x, z) ; // Getting height from ground object

                                                                                                              newInstance.position = new BABYLON.Vector3(x, y, z);
                                                                                                      }
                                                                                            });

                                                                                        }

The idea of using : ground.getHeightAtCoordinates(x, z) was to set each of my meshes in this case "stones" to the ground level on a random location on my scene . The problem starts when i import 1 or more meshes for example a "Palm.babylon or Plant.babylon" that i want to set it in random locations on my scene as well on ground level, then i instanciate and use "var y = ground.getHeightAtCoordinates(x, z) ;" the same way as the stones , but when i load the scene all the meshes doesn't load and i have to reload multiple times so it can appear all the meshes , and sometimes all the meshes never appear .

Surprisingly when  i replace : ground.getHeightAtCoordinates(x, z) to another high for example : 40 or another number , all the meshes appears correctly , that's why i suspect of getHeightAtCoordinates(x, z) function , Not sure if i am doing the correct importing ? , or it has to be something to Unity exporter? or getHeightAtCoordinates() ? , Anyone have an idea of what could be ocurring ?

I wanted to add that if i increment the range of the meshes to be on the scene for example my ground is 1024*1024 and the range of my sheshes is 2048*2048 , all the meshes that are outside the ground appears correctly and the meshes inside the ground doesn't appear , any ideas? maybe it has to be something about memory?

[jerome]

In your snippet we don't know anything about how you built your ground. If your ground is created from a heightmap for instance, you must be sure it's already initialized after the heightmap image download by using the callback function parameter of the groundFromHeighMap constructor static method (this is a common error).

The best way to solve your problem would be :

- to isolate the issue : ex first, not importing anything and using getHeightAtCoordinates(), then if ok, adding the import, etc

- to reproduce it in a PG so we could check the code

[BitOfGold]

I think the issue is, when x and z is over the edge of the ground.
getHeightAtCoordinates does not give you 0 result or something but an error.
Does it give an error on the console?

[JonathanRev]

Good day / night guys , i think i solved it !

@jerome you were totally right , i noticed some of the meshes were loading before the heighmap load completely , that's why i needed to reload many times so all items appears on the scene :

This was the way i was creating the ground : 

                                var ground = BABYLON.Mesh.CreateGroundFromHeightMap("groundterrain", "img/heightmap.png", 1024, 1024, 100, 5, 80, scene, true); 

I solved it this way , correct me if i am wrong please , first of all i used the : onReady method , as i told you before , i am using the "assetsManager" , at the beginning , i was doing this : 

                               ground.onReady = function () {                                       

                                                                      var stones = assetsManager.addMeshTask("stones", "", "assets/stones/", "stones.babylon");

                                                                                     stones.onSuccess = function(task) {

                                                                                            task.loadedMeshes.forEach(function(mesh) {
                                                                                                     mesh.isVisible = false;

                                                                                                     var range = 1024;
                                                                                                     var count = 40;
                                                                                                     for (var index = 0; index < count; index++) {
                                                                                                              var newInstance = mesh.createInstance("j" + index);
                                                                                                              var x = range / 2 - Math.random() * range;
                                                                                                              var z = range / 2 - Math.random() * range;

                                                                                                              var y = ground.getHeightAtCoordinates(x, z) ; // Getting height from ground object

                                                                                                              newInstance.position = new BABYLON.Vector3(x, y, z);
                                                                                                      }
                                                                                            });

                                                                                        }
                                 }

But i noticed the meshes were not appearing with that way, any ideas why ? So , ... i solved it this way instead , adding the assetsManager.load() inside onReady method:

                                ground.onReady = function () {
                                           assetsManager.load();
                                 }

Now everything loads completely without issues or delay.

Btw as you can see i am using the assetsManager , but i also tried using the SceneLoader.ImportMesh this way: 

                                ground.onReady = function () {

                                         BABYLON.SceneLoader.ImportMesh("SmallTree1", "assets/SmallTree1/", "SmallTree1.babylon", scene, function (newMeshes) {

                                     });
                                }

This method also load perfect too , as you can see in the code above i can include the BABYLON.SceneLoader.ImportMesh inside the onReady method , and in this case it works perfect not like the assetsManager.addMeshTask that were not loaded.

 what do you think guys about this methods ? , i don't think it will impact on performance . don't it ? , and sorry if this question is noob but which method on importing objects is the best assetsManager or SceneLoader.ImportMesh ? , in which case do you think is the best on using each? , thanks for your support guys ! i am really grateful to have a great comunity on babylon !