solved update matrix with a clickevent inside shader

[Nabroski]

Hello i'm exploring the matrix func. inside Babylonjs, a matrix lib can be easy
see here : http://glmatrix.net/docs/module-mat4.html
or very hard see here : https://doc.babylonjs.com/api/classes/babylon.matrix

I kind of understand where the problem occurs, after unsucessfull 3h, i think i might be better to ask the community.
Thanks

https://www.babylonjs-playground.com/#Y7Q181

[Guest]

Can you tell us more about what you want to do? Seems unclear to me

Just assuming the problem is in the matrix, let's see what we have here:

let nR = BABYLON.Matrix.Identity();
nR=	BABYLON.Matrix.RotationY(newPosY);
rM=	BABYLON.Matrix.RotationX(newPosX);
rM.multiplyToRef(nR,rM)

This cannot work all xxxToRef functions are used to avoid creating new objects and instead reuse existing one. So for instance the matrix.multiply function will return a NEW matrix where the multiplyToRef will use the last parameter to store the result and thus avoid creating a new matrix

So the correct code should be in your case:

let final = BABYLON.Matrix.Identity();
nR =	BABYLON.Matrix.RotationY(newPosY);
rM =	BABYLON.Matrix.RotationX(newPosX);

// Multiply rM by nR and store the result in final
rM.multiplyToRef(nR,final)

If you don't want xxtoRef functions, you can use this code (probably easier to read but less efficient as it will put pressure on the GC):

nR =	BABYLON.Matrix.RotationY(newPosY);
rM =	BABYLON.Matrix.RotationX(newPosX);

// Multiply rM by nR and store the result in final
let final = rM.multiply(nR)

 

[Nabroski]

Hello
thank you

i try simple to multiply to matrieces ( how hard can it be ) https://en.wikipedia.org/wiki/Rotation_matrix#Basic_rotations

 

http://glmatrix.net/docs/mat4.js.html#line584 multiply by http://glmatrix.net/docs/mat4.js.html#line541
 

let rMat = mat4.create(); 
mat4.identity(rMat);

canvas.addEventListener

const nRot = mat4.create();
mat4.rotateY(nRot, nRot, (deltaX *0.5)*0.01 );
mat4.rotateX(rMat, rMat, (deltaY *0.5)*0.01 );
mat4.multiply(rMat, nRot,rMat);

canvas.addEventListener end

requestAnimationFrame

gl.uniformMatrix4fv(uLocRot, false, rMat);

requestAnimationFrame end
 // and it's working

 

Yes, but the Matrix resets its self, see here: 

https://www.babylonjs-playground.com/#Y7Q181#2

@DeltakoshRaw WebGL
http://bl.ocks.org/tolkanabroski/3fcaab9467652a797851c7e080976f09

[Guest]

What do you mean by "reset itself" ?

[Nabroski]

i guess becourse of 
scene.onBeforeRenderObservable.add or any other renderloop inside the createScene the Matrix isent stored properly. 

 

(

i leave this here, for later for debuging reasons

# just an other debug playground
https://www.babylonjs-playground.com/#Y7Q181#4

# minimal copy paste from the docs

https://www.babylonjs-playground.com/#Y7Q181#3

)

 

Dont worry i will investigate :)

 

 

[Nabroski]

on other hand i spend already like 6h hours with a simple matrix multiplication, i code this like in 10min. if anyone has suggestions. ur welcome
https://www.babylonjs-playground.com/#Y7Q181#5

[Nabroski]

24h later ended up implementing my own matrix operations (its working now, (no wonder))
have to figure out how to stack different pointer events ...
i leave it here, maybe some1 find it useful.
https://www.babylonjs-playground.com/#Y7Q181#6

 

BabylonJS Unsolved Mysteries (to be continued)

[Guest]

Quote

BabylonJS Unsolved Mysteries (to be continued)

lol