OPTIMIZE_WITH_UV causes un-smoothed normals after recomputing

[Numa]

Hi there, 

If you load an obj with the flag OPTIMIZE_WITH_UV=true then recompute the normals, you lose the smoothing.

playground: (switch line 14 from true to false hehe)

http://www.babylonjs-playground.com/#1U5GPV#50

Right now I have to pick between broken texture (flag set to false) or broken normals (flag set to true)  

any ideas?

 

Thanks

[adam]

This looks like the same issue you had in the other thread.

 

[Numa]

yes but I edited the other post and started this new one, as the problem is not at all what I thought it was  it has nothing to do with me moving verts. It's just that the "optimization" flag in the obj loader causes the normals to not recalculate correctly.

 

 

[adam]

I don't think you need to set the vertices after recomputing the normals.

If you have to, VertexData.applyToMesh seems to work:

http://www.babylonjs-playground.com/#1U5GPV#52

[Numa]

Yes it looks like the change only takes effect if you reapply the vertex data (I can see it on another model where it affects the lighting)

I'm wondering how this even runs in the playground, there is a typo line 31, "inices" instead of "indices". If you fix the typo, it doesn't smooth  

I got excited for a moment

 

[adam]

18 minutes ago, Numa said:

there is a typo line 31, "inices" instead of "indices".

[adam]

Here is the OPTIMIZE_WITH_UV code:

https://github.com/BabylonJS/Babylon.js/blob/ba0e165c15a9520ace97c585d30c0dd692cda058/loaders/src/OBJ/babylon.objFileLoader.ts#L335

and the computeNormals code:

https://github.com/BabylonJS/Babylon.js/blob/372050675a052c3aa55a0a3e6b77186f51cf2114/src/Mesh/babylon.mesh.vertexData.ts#L2065

Maybe you can see something there that will give you an idea what is causing the issue.

[Numa]

thanks, I had a look and from what I can tell it only affect this function, which to be honest looks like minified code

var isInArrayUV = (arr: Array<{ normals: Array<number>; idx: Array<number>; uv: Array<number> }>, obj: Array<number>) => {
                if (!arr[obj[0]]) arr[obj[0]] = { normals: [], idx: [], uv: [] };
                var idx = arr[obj[0]].normals.indexOf(obj[1]);

                if (idx != 1 && (obj[2] == arr[obj[0]].uv[idx])) {
                    return arr[obj[0]].idx[idx];
                }
                return -1;
            };

Do we know who wrote the obj loader? I'd love to understand what this does

[adam]

This does look like a bug.  

I tried a different approach and I get the same results:

http://www.babylonjs-playground.com/#1U5GPV#58

[Numa]

yep I agree  Should I log it in the "bug" thread?

[NasimiAsl]

this is not a bug

recompute calculate new normal with face points when we import .obj (with last uv ) with SceneLoader 

algorithm make separated face so recomputed method create flat normal

the best way to have correct normal is import that normal from obj and recalculate always have some part of data 

i work on new importer but i just can correct  non edge(uv edge) part of mesh

left : last uv + recompute 

center : raw object + recompute

right : scene loader 

http://www.babylonjs-playground.com/#D6IPT#5

bird : http://www.babylonjs-playground.com/#D6IPT#7

textured : http://www.babylonjs-playground.com/#D6IPT#6

solution :

1.import raw obj 

2.recompute normals

3. correct last uv problem + append new normal to created face

i need time to fix some bug and import this stuff 

 

 

 

[Numa]

This looks great @NasimiAsl, let me know when I can start using this

[Numa]

Hi @NasimiAsl, any progress on this?

[NasimiAsl]

@Numa

hi   i have 3 small problem for that  but  i can't work in this week (hope start some stuff about babylonjs in next week )

[Dad72]

1 hour ago, NasimiAsl said:

(hope start some stuff about babylonjs in next week

You think also finish with the fusion of standardMaterial and ShaderBuilder?

[NasimiAsl]

@Dad72 yes "start some stuff " mean start working about standardmaterial and some others 

[Dad72]

Cool, thanks.