Problem of color rendering of a Blender object

[Dams]

Hello guys,

I am experiencing a weird behavior with Blender and Babylon on the color of my object.

I created a simple Mesh in Blender: a plate with Subdivision Surface then I extruded one side and use Crease parameter on edge to get a nice roundish.

When playing with it in Babylon.js, the rendering is really weird: color is not the same aspect on all the surface and on the bottom face as well.  

 

My code is pretty simple:

BABYLON.SceneLoader.ImportMesh(…)

pbr_material = new BABYLON.PBRMaterial("pbr_material", scene);

pbr_material.microSurface = 0.96;

pbr_material.albedoColor = new BABYLON.Color3(0.206, 0.94, 1);

pbr_material.reflectivityColor = new BABYLON.Color3(0.05, 0.05, 0.05);

pbr_material.cameraExposure = 0.66;

pbr_material.cameraContrast = 1.66; 

 

Even in SandBox, my object looks not homogenous.

I tried many many ways (change mesh/vertice in Blender, play with light, colors…) to understand this behavior unfortunately without success…

 

Do you have any ideas to solve that?

Thank you very much !

 

 

 

TestSubSurf02.babylon

[Wingnut]

Hi @Dams, welcome to the BabylonJS forum.  Sorry to hear you are having problems.  It's probably inverted normals or something like that.  Who knows what evil those darned Blender crease-benders... do. 

I noticed you said "plate" and not "plane".  That's interesting in itself.  A plate being somewhat like a box?  *shrug*

No matter.  I published your .babylon file to my github nest, and kindly escorted it into our cool BabylonJS online playground.  Take a look, if ya please:

http://playground.babylonjs.com/#WMW8#1

Yep, it looks kind of strange.  I'm not sure what's wrong, but I'll stare at it and think about it. 

Maybe others will jump-in and have some good ideas.  I still suspect normals.  Got a re- computeNormals choice in Blender?  Maybe there's one here.  Something is not normal about your normals.    Talk more soon.

[gryff]

18 hours ago, Dams said:

I created a simple Mesh in Blender: a plate with Subdivision Surface then I extruded one side

Hi @Dams : welcome to the forum.:)

My experience is that with Blender and the "Extrude" functionality - always recalculate normals afterwards.

cheers, gryff

[Dams]

Hi @Wingnut and @gryff !!

Thanks a lot for your replies !

I recalculated Normals under Blender (edit mode > A (to select all faces) > Recalculate ("Inside" checked and uncheked). But unfortunately, it does not change anything ! :-(

I need you to give me some advice to solve this problem. Any other idea ?

Thank you very much !

 

[Pryme8]

http://www.html5gamedevs.com/topic/24438-edit-material-of-importmesh-obj/

[JCPalmer]

If it were I, the tests I would do are:

• See if the Blender geometry looks "OK" without all this PBR post import stuff.
• Try your PBR code on a plane or cube created right from BJS.

Divide an conquerer, should be in everyones toolkit.

[aWeirdo]

Hi, @Dams 

i'll jump in with a quick note, the colour's you see on any object with curves/bends will vary slightly, due to lightning not being able to reach all areas with the same "strength" / intensity.

and as others already mentioned it, also seemed like you had a slight issue with your normals in your pictures.

I didn't quite understand what you were after, but using @Wingnut's PG as a base, this is what i got.
Note that i reduced the light intensity slightly for better contrast between the edges & sides of the mesh, aswell as disabled backFaceCulling.

Take a look at this PG: http://playground.babylonjs.com/#WMW8#4

[gryff]

2 hours ago, aWeirdo said:

I didn't quite understand what you were after, but using @Wingnut's PG as a base, this is what i got.
Note that i reduced the light intensity slightly for better contrast between the edges & sides of the mesh, aswell as disabled backFaceCulling.

Nicely done @aWeirdo ! If disabling backFaceCulling is producing the correct results then it seems to me again that it is a problem with the normals.

 

21 hours ago, Dams said:

I recalculated Normals under Blender (edit mode > A (to select all faces) > Recalculate ("Inside" checked and uncheked). But unfortunately, it does not change anything ! :-(

I'm not sure what @Dams means by ""Inside" checked and uncheked" but I would Select all the faces ->Normals-> "Recalculate Normals Outside".  Clicking on the "Inside" option just recalculates them on the inside, and it does not toggle them by clicking a second time

cheers, gryff

[Nabroski]

https://www.blender.org/manual/modeling/meshes/editing/normals.html

https://www.reddit.com/r/blender/comments/1lkijw/shading_options_multitexture_vs_singletexture_vs/

 

 

[Dams]

Thanks to aWeirdo, the result is better but still weird with an object bigger... I need to investigate much more to solve this behavior.

For the normals, I found the good way on Blender but still not expecting an acceptable result... I even tried to flip the top face to understand the way it works but nothing helps... On Blender, Normals seem OK for all faces :-(

Maybe it comes from my object in Blender with the way I draw it... I will try other shapes.

If you still have ideas, I will take it :-)

[Dams]

I am back to you as unfortunately I am still in the mess :-(

My Normals seem OK (see image enclosed) ; and I recalculated them under Blender and by code (as suggested by Pryme8) but the result is still not acceptable… (see image enclosed).

 

I did several tests on Blender side and the behaviour occur when I create rounding (with Subdivision Surface).

 

The problem is the same with PBR material and Standard one…

 

aWeirdo, you found a quite nice equation on my first drawing. Are you able to do the same with this bigger drawing? I need you. It will be very nice!

 

Maybe I should use another technique on Blender to do a rounding. If someone has any idea ?

TestSubSurf04.babylon

TestSubSurf04.blend

[Pryme8]

Your not happy with the Phong angles?  or the normals are still not coming into calculation?

Im confused on whats really the problem now.

 

[Nabroski]

Hello

i'm sorry i have no time to look at your files, but i think this is just a light reflection. When you see this white plane, this is the light hitting the surface from below. 

[Dams]

Unfortunately i tried to play with different lights and different orientation without success.

Do you have any advice on lighting ?

Thank you !

[gryff]

@Dams : I took a look at your .blend file and added a Hemi lamp directly above the "table" then rendered it in Blender - both the "Cycles" and "Blender" renderer see top part of image below.

I exported the from Blender to a .babylon file and viewed that in the Babylon sandbox - lower part of image.

To me a Hemi lamp emits light as shown in the attached pic with light coming from all directions

:

yet the ends of the table look like they are not receiving light in this manner - rather the light is coming straight down.

And just so you know, I applied the Subsurf Modifier first and then checked the normals

cheers, gryff

[Nabroski]

9 hours ago, Dams said:

Unfortunately i tried to play with different lights and different orientation without success.

Do you have any advice on lighting ?

Thank you !

Hello

long story short, you can give a picture depth by just adding shadows somewhere, this is art history. All of the provisos achievements have been also applied to the present. That you can draw a simple line on your screen, goes back to a crazy math formula in the 19th century  

if you want a crash course in lightning go on youtube an watch a tutorial how to set up a lighting for studio shooting. The digital emulation of reality is pretty accurate those days

Best

[Dams]

Hi Gryff,

Thanks a lot for your experimentation but i certainly missed something :

- the model is fine under Blender (all surface look the same)

- the model is NOT looking fine with Babylon.js even when using a Hemi light. And that is the problem ! And I am sorry but i still do not understand how to solve that... ?

@Nabroski : i will Google lighting for studio shooting. Thanks.

[Pryme8]

It's your normals then.

 

please send me a link to the model in question lets get this taken care of today.

[Dams]

Hi. I posted my .blend file in my post of wednesday. Here it is:

http://www.html5gamedevs.com/applications/core/interface/file/attachment.php?id=9077

It will be so nice if you are able to solve it !! :-)

Thanks in advance. 

[Pryme8]

Once I finish my morning routine here I'll give it a look.  Can you send me a link to the object you made the blend file with preferabley and obj.

[Nabroski]

interessting, i just want to share some code, sorry, a bit offtopic

http://babylonjs-playground.com/#1AYM1C#4

or you just set up your lighting from two opposite directions 

[Dams]

Hi Pryme8,

Please find files here : https://dl.dropboxusercontent.com/u/75748606/MyFiles.zip

Thanks !

[Pryme8]

My girlfriend is telling me I stink so Im gonna go take a shower then Ill handle this after.  Talk to you soon.

[Dams]

OK :-) 

I will wait a little ;-)

[Dams]

@Nabroski Interesting ! It may help me. Thanks !