transparency fails?

fitfool · Post by **fitfool** » Sat Jun 21, 2008 6:34 am

Im trying to implement vertex transparancy in irrlicht but aren't getting any results, my mesh is still completely visible.

Heres what im doing now.

Code: Select all

GetSceneNode()->setMaterialTexture( 0, Core.CoreVideoDriver->getTexture(BOX_TEXTURE) );
	GetSceneNode()->getMaterial( 0 ).MaterialType = EMT_TRANSPARENT_VERTEX_ALPHA;
	GetSceneNode()->setMaterialFlag( EMF_LIGHTING, false );
GetSceneNode()->getMaterial( 0 ).AmbientColor.setAlpha( 100 );

Thanks ahead

arras · Post by **arras** » Sat Jun 21, 2008 6:58 am

I do not see any code which actually changes vertex color alpha and set it to transparent. If your vertices are not transparent, setting material to EMT_TRANSPARENT_VERTEX_ALPHA will do nothing.

fitfool · Post by **fitfool** » Sat Jun 21, 2008 6:58 pm

I see, is there anyway i can just call GetSceneNode()->getMaterial( 0 ).AmbientColor.setAlpha( 100 ) and will make the whole mesh appear transparent? without having to iterate over all vertices and such?

hybrid · Post by **hybrid** » Sat Jun 21, 2008 9:51 pm

No, you can either use vertex alpha or texture alpha.

arras · Post by **arras** » Sun Jun 22, 2008 7:43 am

But you can use virtual void IMeshManipulator::setVertexColorAlpha (IMesh *mesh, s32 alpha)

fitfool · Post by **fitfool** » Mon Jun 23, 2008 7:31 am

Thanks, but what if i have muiltiple instances of that mesh and want to 'have' a different alpha for each?

hybrid · Post by **hybrid** » Mon Jun 23, 2008 8:45 am

Create a mesh copy for each one? If there are too many vertices to do y setVertexColor in each frame it seems like the only option. Or create separate textures and use alpha channel transparency, would require separate textures for each mesh, though.

BlindSide · Post by **BlindSide** » Mon Jun 23, 2008 10:51 am

Check out the shader example in the SDK (Number 10), that shows how to very easily manipulate alpha using shaders in Irrlicht.

You can create a vertex-only shader, and use as it's base material (The second to last parameter) EMT_TRANSPARENT_VERTEX_ALPHA, then output whatever vertex color you want based on a shader uniform. To use a vertex-only shader just use NULL for the pixel shader filename parameter in "addHighLevelShaderMaterialFromFiles". Vertex-only shaders are even supported on MX440's so you don't really have to worry about compatibility in this case.

Cheers

fitfool · Post by **fitfool** » Tue Jun 24, 2008 8:08 pm

Hmm, i was hoping to avoid using shaders, ill try creating a new mesh instance for each, well... instance. Thanks a bunch

Hmm, btw, how should i use IMeshManipulator::setVertexColorAlpha? Is there any method within IAnimatedMesh were i can get() a IMeshManipulator?

arras · Post by **arras** » Wed Jun 25, 2008 9:34 am

You can get it in: ISceneManager::getMeshManipulator()

fitfool · Post by **fitfool** » Wed Jun 25, 2008 9:59 pm

Works perfectly, thanks a bunch