Script LOD Systeme

[Dad72]

Hi,
 
I create a small script of LOD and I want to share it. I don't know if it's the best ways to make, so if you want to improve it please do not hesitate.
 

			var BABYLON = BABYLON || {};			(function () {					// DistanceLOD1 = medium				// DistanceLOD2 = low				// DistanceMax = hide				BABYLON.DistanceLOD1 = 10;				BABYLON.DistanceLOD2 = 30; 				BABYLON.DistanceMax = 50;											// LOD_0 = hight				// LOD_1 = medium				// LOD_2 = low					BABYLON.LOD = function(Camera, LOD_0, LOD_1, LOD_2)				{					this.camera = Camera;					this._verifInProgress = false;									this._distance = 0;					this.LOD0 = LOD_0;					this.LOD1 = LOD_1;					this.LOD2 = LOD_2; 					this.positionLOD0 = this.LOD0.position;					if (this.LOD1 != undefined) this.LOD1.setEnabled(false);      					if (this.LOD2 != undefined) this.LOD2.setEnabled(false); 				};   								BABYLON.LOD.prototype._distanceTransition = function() 				{					if (this.LOD1 != undefined || this.LOD2 != undefined)					{						this._distance = this.camera.position.subtract(this.positionLOD0).length();											var enableLOD0 = this._distance < BABYLON.DistanceLOD1;						this.LOD0.setEnabled(enableLOD0);						var enableLOD1 = !enableLOD0 && this._distance < BABYLON.DistanceLOD2;						if (this.LOD1 != undefined)						{							this.LOD1.setEnabled(enableLOD1);						}						if (this.LOD2 != undefined)						{							this.LOD2.setEnabled(!enableLOD0 && !enableLOD1 && this._distance <= BABYLON.DistanceMax);						} 					}						};					BABYLON.LOD.prototype.Update = function()				{					if (this._verifInProgress) return;							this._verifInProgress = true;					this._distanceTransition();					this._verifInProgress = false;				};							})();						

Use:

							//Sphere Hight				var sphere0 = BABYLON.Mesh.CreateSphere("Sphere_Higth", 50.0, 1.0, scene);				var materialSphere0 = new BABYLON.StandardMaterial("color1", scene);				materialSphere0.diffuseColor = new BABYLON.Color3(1.0, 0.2, 0.7);				sphere0.material = materialSphere0;				//Sphere Medium				var sphere1 = BABYLON.Mesh.CreateSphere("Sphere_Medium", 7.0, 1.0, scene);				var materialSphere1 = new BABYLON.StandardMaterial("color2", scene);				materialSphere1.diffuseColor = new BABYLON.Color3(1.0, 0, 0);				sphere1.material = materialSphere1;				//Sphere Low				var sphere2 = BABYLON.Mesh.CreateSphere("Sphere_Low", 2.0, 1.0, scene);				var materialSphere2 = new BABYLON.StandardMaterial("color3", scene);				materialSphere2.diffuseColor = new BABYLON.Color3(0, 0, 0);				sphere2.material = materialSphere2;				// Initialise LOD 				var lodObjet = new BABYLON.LOD(camera, sphere0, sphere1, sphere2);												engine.runRenderLoop(function () {					scene.render();					lodObjet.Update(); // Update Transition LOD				});

I have yet to test the script, but this should work.

Demo:
http://www.castorengine.com/babylon/LOD/

[gwenael]

Thanks for sharing.

 

Here are my feedbacks:

 

* that would be better to set verifInProgress only in one function and to indicate that's a private member

BABYLON.LOD.prototype.Update = function() {    if (this._verifInProgress) {        return;    }    this._verifInProgress = true;    this._distanceTransition();    this._verifInProgress = false;};

* DistanceTransition should also be marked as private _distanceTransition instead of DistanceTransition

* this.distance is correct if LOD0 is in the same space as camera (they share the same parent or they both don't have parents); it should also be private since it should only be used internally

* "if, else" can be simplified

* Why do you always call BABYLON.LOD.sleep even if this.LOD1 == undefined && this.LOD2 == undefined? By the way, why do you wait an amount of seconds at the end of _distanceTransition?

BABYLON.LOD.prototype._distanceTransition = function() {   if (this.LOD1 != undefined || this.LOD2 != undefined) {         this._distance = this.camera.position.subtract(this.positionLOD0).length();					         var enableLOD0 = this._distance < BABYLON.LOD.DistanceLOD1;         this.LOD0.setEnabled(enableLOD0);         var enableLOD1 = !enableLOD0 && this._distance < BABYLON.LOD.DistanceLOD2;         if (this.LOD1 != undefined) {            this.LOD1.setEnabled(enableLOD1);         }         if (this.LOD2 != undefined) {            this.LOD2.setEnabled(!enableLOD0 && !enableLOD1 && this._distance <= BABYLON.LOD.DistanceMax);         }       }    BABYLON.LOD.sleep(BABYLON.LOD.delaiSeconds);};

* You can modify BABYLON.LOD.sleep as is:

BABYLON.LOD.sleep = function(seconds) {    var start = new Date().getTime();    while((new Date().getTime() - start) <= (seconds * 1000)) {     // wait    }};

[Dad72]

Thanks for the changes. I've edit the first post to reflect the changes. I think that DeltaKosh will do a system more adequate in the futures.

To BABYLON.LOD.sleep, it is to give a pause of  +- 5 seconds between each loop of runRenderLoop towers. but I confess to not being sure about this approach and the result.

 

Like I said ,I do not have tested my script, I made this script to pass the time and I said to myself that this could be useful for testing the LOD while waiting for Deltakosh creates the official LOD system.

[Dad72]

Update LOD script that works now. I tested.

 

I set the aperture first post with a complete code (html + js) to test

[Dad72]

I add a direct link test system LOD:

 

Use the keyboard arrows to move back and forth, you will see the transitions

 

http://www.castorengine.com/babylon/LOD/

[gryff]

I add a direct link test system LOD:

 

Use the keyboard arrows to move back and forth, you will see the transitions

 

http://www.castorengine.com/babylon/LOD/

 

Nice dad72 - seems to work well

 

while waiting for Deltakosh creates the official LOD system

 

I remember seeing LOD on the to-do-path when I first joined this forum - but then DK and crew have a lot of stuff to do, so I guess it is a matter of priorities

 

cheers, gryff

[Temechon]

I think they are working on it... But great job Dad ! Works great !

[Dad72]

Thanks guys !