why are the Y and Z axis different in JSCAD vs. THREE?

[tsdexter]

@z3dev why are the axis' transposed vs THREEjs?

For example, rendering the primitives3D example in each has them oriented differently with Z pointing upwards in JSCAD whereas Y points upwards in THREE:

[tsdexter]

@hrgdavor did you come across this when messing with THREE as well?

[hrgdavor]

it is simply the choice of default UP direction, none is correct/incorrect. If you want your scene in THREE to match jscad orientation just use

camera.up.set(0, 0, 1)

... also in babylonjs the default triangle orientation is different than threejs CW/CCW choice is one more of those things where there is a chance some use one or the other and there is no definitive right choice as far as I know.

[tsdexter]

great thanks, I'll try that out tomorrow.

[tsdexter]

@hrgdavor @z3dev can you point me in the right direction for how the transforms property on the models works? For example:

console.log(rotate([degToRad(45), 0, 0], cuboid({size: [1,2,10], center: [2, 2, 2]})))

Logs:

{
  polygons: ...
  transforms:  [1, 0, 0, 0, 0, 0.7071067811865476, 0.7071067811865475, 0, 0, -0.7071067811865475, 0.7071067811865476, 0, 0, 0, 0, 1]
}

What do the 16 values represent?

I was using 0, 5, 10 as the scale and 12, 13, 14 as the position determined via basic inspection of the values. That seemed to be working with basic cubes/translates/etc. Then I added some rotations and it's clearly not accurate.

How can I accurately map the transforms array to data like position, scale, rotation for use with a three mesh or elsewhere?

[hrgdavor]

in jscadui there is compatibility layer for threejs, and in there is snippet how to apply transform from jscad
https://github.com/hrgdavor/jscadui/blob/2f1f8b73b235b16d80f9ff1bdd64bcd8090ae10e/packages/format-threejs/index.js#L88

jscadui supports multiple render engines so it first converts to common format and then to threejs or babylon or regl

common format
https://github.com/hrgdavor/jscadui/tree/main/packages/format-common

jsacd to common:
https://github.com/hrgdavor/jscadui/blob/main/packages/format-jscad/index.js

common to threejs
https://github.com/hrgdavor/jscadui/tree/main/packages/format-threejs

[tsdexter]

Nevermind. I see that it is a transformation matrix which I can pass to directly to mesh.matrix and turn off mesh.matrixAutoUpdate which seems to be working!

[tsdexter]

@hrgdavor didn't see your reply. Thanks - I'll look through the links provided to get a little more insight into how it's working!

[tsdexter]

@hrgdavor I can't use three controls with mesh.matrixAutoUpdate=false so I will have to look further at what you did to apply the JSCad transformations to the existing three matrix. Thanks!

[tsdexter]

@hrgdavor thanks! I got it working with:

meshRef.applyMatrix4({elements: model.transforms})