Probleme with transparency

Thulsa Doom · Post by **Thulsa Doom** » Fri Oct 22, 2004 8:51 am

Anonymous wrote:Not much luck ... if i set a grey texture (R 128 G 128 B 128) then i get a better result but not ok. And if an object gets in front of the "transparent" mesh it also gets transparent.

With the opengl driver the effect is much better but it stays at 50% transparent no matter what the alpha value is.

Have not observed that. Is the object in front totally transparent or only partially in overlapping areas?

POi · Post by **POi** » Fri Oct 22, 2004 2:29 pm

Here is a little example ... i have enabled the vertex color alpha (due to hireacial objects in .x file not all objects even get affected with the alpha value but thats another issue) and the render order seems all messed up. Anyway on the right you se a small round object and on the left i have rotated the view a bit so it gets in front of the rest of the mesh and it dissapears (probably renders behind), The same thing happens if i have a water plane running in the middle of the mesh. When vertex col. aplha is set then the waterplane always renders in front of the mesh.

//POi

POi · Post by **POi** » Sat Oct 23, 2004 7:21 am

Any ideas ?

POi · Post by **POi** » Wed Oct 27, 2004 5:59 am

Any news ?

Guest · Post by **Guest** » Wed Oct 27, 2004 6:03 am

i think there is no solution.
probably a bug with EMT_TRANSPARENT_ALPHA_CHANNEL ?
i don't no

Magnet · Post by **Magnet** » Thu Sep 28, 2006 8:53 am

I seem that transparency is does not work.
I not even can create box with 20% transparency.

Code: Select all

C#:

            ITexture texWall = device.VideoDriver.GetTexture(@"..\..\media\wall.bmp");
            ISceneNode node = device.SceneManager.AddCubeSceneNode(15,
                   null, -1, new Vector3D(30, -15, 0));
            Material mat = new Material();
            mat.Lighting = false;
            mat.BackfaceCulling = false;
            mat.Texture1 = texWall;
            mat.Type = MaterialType.TRANSPARENT_ADD_COLOR;
            mat.EmissiveColor.Alpha = 10;
            mat.DiffuseColor.Alpha = 10;
            mat.AmbientColor.Alpha = 10;
            mat.SpecularColor.Alpha = 10;            
            node.SetMaterial(0, mat);

This box is 50% transparent. How to set 5% transparent for example?

hybrid · Post by **hybrid** » Thu Sep 28, 2006 8:59 am

Please don't cross post your questions all over, and only raise such old threads if this is really useful!
TRANSPARENT_ADD_COLOR takes the texel color and makes the texel transparent based on the color value (thus black becomes completely transparent, while white is completely opaque). You can also use vertex color alpha and texture alpha channel for the transparency by choosing the correct material. I don't know about light alpha settings to do anything useful.

Magnet · Post by **Magnet** » Thu Sep 28, 2006 9:39 am

Please, write me code which create in scene 5% transparant box with texture.
I can't set transparency for object.

Xaron · Post by **Xaron** » Thu Sep 28, 2006 10:48 am

Code: Select all

smgr->getMeshManipulator()->setVertexColors( mesh, video::SColor( color, color, color, color ) );

This does work if I use EMT_TRANSPARENT_ADD_COLOR as material.

But it would be useful to have a real transparency for any scene node to fade things...

Regards - Xaron

Magnet · Post by **Magnet** » Thu Sep 28, 2006 11:57 am

Hm..
But first parametr is IMesh...possible do this for any ISceneNode or at least for CubeSceneNode

Xaron · Post by **Xaron** » Thu Sep 28, 2006 12:52 pm

Magnet wrote:Hm..
But first parametr is IMesh...possible do this for any ISceneNode or at least for CubeSceneNode

This won't work as this is not yet implemented. There is no way to fade out or set an alpha for a complete scene node.

Regards - Xaron

Magnet · Post by **Magnet** » Fri Sep 29, 2006 12:34 pm

I am create new code:
This code build full scene:

Code: Select all

IMesh * mesh=smgr->getMesh("../storage/AquaBox/AquqBox.x")->getMesh(0);
smgr->getMeshManipulator()->setVertexColors( mesh, video::SColor( 25, 255, 255, 255 ) ); 
ISceneNode *Aqua = smgr->addMeshSceneNode(mesh);
Aqua->setMaterialFlag(EMF_LIGHTING, false);	
Aqua->setAutomaticCulling(false);
Aqua->setMaterialFlag(EMF_BACK_FACE_CULLING, false);
smgr->addCameraSceneNodeMaya();

But my model is not transparent

Please fix this code.[/code]

Magnet · Post by **Magnet** » Fri Sep 29, 2006 12:44 pm

Many thanks!!!!
I am not set material type to EMT_TRANSPARENT_VERTEX_ALPHA
My object is transparent by this code:

Code: Select all

	IMesh * mesh=smgr->getMesh("../storage/AquaBox/AquqBox.x")->getMesh(0);
	smgr->getMeshManipulator()->setVertexColors( mesh, video::SColor( 100, 100, 100, 100 ) ); 
	ISceneNode *Aqua = smgr->addMeshSceneNode(mesh);
	Aqua->setMaterialFlag(EMF_LIGHTING, false);	
	Aqua->setAutomaticCulling(false);
	Aqua->setMaterialFlag(EMF_BACK_FACE_CULLING, false);
	Aqua->setMaterialType(video::EMT_TRANSPARENT_VERTEX_ALPHA  );
	smgr->addCameraSceneNodeMaya();