Sphere+BitmapMaterial+PhongShader=Artefacts

[Markus Ebbighausen]

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Hi Papervision-list,

 

I have some trouble with 3D-Objects (no matter if primitives or Collada) and applied shaded material on them.

What happens is, that I do have these nasty black artefact-lines.

 

What I wanted to get:

Loading a collada-Object through the DAE-parser into PV3D and applying a phong-shaded BitmapMaterial to it.

 

What I got:

Ugly black artefacts on the „corner“ of the 3D-Object.

Result can viewed here: http://www.mediaville.de/lab/collada_tests/3/

 

Then I thought it might be something wrong with the 3D-Model, so I decided to do the same with a primitive of Papervision. But I got the same ugly artefacts.

Result can be seen here: http://www.mediaville.de/lab/sphere_with_shading_bug/

 

In the same code-sample I now integrated the possibility to switch bewtween different materials mapped to the sphere by pressing 1 to 5 on the numeric keypad. These artefacts can only be seen with the combination of a BitmapMaterial and a Shader (no matter which one). If you apply the same loaded Bitmap-Texture as a MovieMaterial (without shader) to the sphere (hit „5“ on the above sample), there are no artefacts. And if you apply the PhongMaterial onto the sphere (hit „4“) it’s the same. So it doesn’t seem to be neither the material nor the Shader. But the combination of it?!

 

How I coded it (using PV3D 2.1.920):

I loaded the bitmap through a loader and added an EventListener:

 

var imgLoader:Loader = new Loader();

imgLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, bitmapMaterialLoaded);

imgLoader.load(new URLRequest("assets/textures/orange.png"));

 

In the „bitmapMaterialLoaded“-Handler I shaded the image and applied it to a sphere:

 

var bitmap:Bitmap = e.target.content as Bitmap;

var bmMaterial:BitmapMaterial = new BitmapMaterial(bitmap.bitmapData);

var light:PointLight3D = new PointLight3D(true, true);

var phongShader:PhongShader = new PhongShader(light, 0xFFFFFF, 0x999999);

var shadedBitmapMaterial: ShadedMaterial = new ShadedMaterial(bmMaterial, phongShader);

var sphere:Sphere = new Sphere(shadedBitmapMaterial, 500);

scene.addChild(sphere);

 

I tried to get an answer in the shortly released book „Papervision3D Essentials“ (great work, my compliments to the auhors Jeff Winder and Paul Tondeur) but unfortunately I couldn’t. Also I had a look in the Papervision-Forum, but also no results that helped me further.

 

What I found was an article about the same phenomenon: http://www.nabble.com/BitmapMaterial-%2B-PhongShader-%2B-DAE.--Why-black-lines-on-the-material--td18491117.html. There was the conclusio (back in january 2009) that „skinned or animated DAEs are not properly working“. With the above sphere-example this can’t be the solution form y problem. I also tried to use different types of renderer – with no success.

 

Please, does anybody know what’s going wrong???

 

The full code and the used texture is attached to this mail.

 

Thanks in advance,

Markus

 

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[JohnBrookes]

I'm sure I read the problem was rounding errors with UV seams.

Basically for shaders to work (no black lines), you have to have a single UV shell with the seam mapped to the UV square.

My theory anyway.

2009/10/27 Markus Ebbighausen <[hidden email]>

Hi Papervision-list,

 

I have some trouble with 3D-Objects (no matter if primitives or Collada) and applied shaded material on them.

What happens is, that I do have these nasty black artefact-lines.

 

What I wanted to get:

Loading a collada-Object through the DAE-parser into PV3D and applying a phong-shaded BitmapMaterial to it.

 

What I got:

Ugly black artefacts on the „corner“ of the 3D-Object.

Result can viewed here: http://www.mediaville.de/lab/collada_tests/3/

 

Then I thought it might be something wrong with the 3D-Model, so I decided to do the same with a primitive of Papervision. But I got the same ugly artefacts.

Result can be seen here: http://www.mediaville.de/lab/sphere_with_shading_bug/

 

In the same code-sample I now integrated the possibility to switch bewtween different materials mapped to the sphere by pressing 1 to 5 on the numeric keypad. These artefacts can only be seen with the combination of a BitmapMaterial and a Shader (no matter which one). If you apply the same loaded Bitmap-Texture as a MovieMaterial (without shader) to the sphere (hit „5“ on the above sample), there are no artefacts. And if you apply the PhongMaterial onto the sphere (hit „4“) it’s the same. So it doesn’t seem to be neither the material nor the Shader. But the combination of it?!

 

How I coded it (using PV3D 2.1.920):

I loaded the bitmap through a loader and added an EventListener:

 

var imgLoader:Loader = new Loader();

imgLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, bitmapMaterialLoaded);

imgLoader.load(new URLRequest("assets/textures/orange.png"));

 

In the „bitmapMaterialLoaded“-Handler I shaded the image and applied it to a sphere:

 

var bitmap:Bitmap = e.target.content as Bitmap;

var bmMaterial:BitmapMaterial = new BitmapMaterial(bitmap.bitmapData);

var light:PointLight3D = new PointLight3D(true, true);

var phongShader:PhongShader = new PhongShader(light, 0xFFFFFF, 0x999999);

var shadedBitmapMaterial: ShadedMaterial = new ShadedMaterial(bmMaterial, phongShader);

var sphere:Sphere = new Sphere(shadedBitmapMaterial, 500);

scene.addChild(sphere);

 

I tried to get an answer in the shortly released book „Papervision3D Essentials“ (great work, my compliments to the auhors Jeff Winder and Paul Tondeur) but unfortunately I couldn’t. Also I had a look in the Papervision-Forum, but also no results that helped me further.

 

What I found was an article about the same phenomenon: http://www.nabble.com/BitmapMaterial-%2B-PhongShader-%2B-DAE.--Why-black-lines-on-the-material--td18491117.html. There was the conclusio (back in january 2009) that „skinned or animated DAEs are not properly working“. With the above sphere-example this can’t be the solution form y problem. I also tried to use different types of renderer – with no success.

 

Please, does anybody know what’s going wrong???

 

The full code and the used texture is attached to this mail.

 

Thanks in advance,

Markus

 

_______________________________________________
Papervision3D mailing list
[hidden email]
http://osflash.org/mailman/listinfo/papervision3d_osflash.org

_______________________________________________
Papervision3D mailing list
[hidden email]
http://osflash.org/mailman/listinfo/papervision3d_osflash.org