Problem with alpha blending!

Troubleshooting General Help
1

    hi,there.



    I want to place something into an transparent cylinder. But I can't see what I placed outside the cylinder.How to make them visable?



    here is the code.

   

    AlphaState as1 = display.getRenderer().createAlphaState();

    as1.setBlendEnabled(true);

    as1.setSrcFunction(AlphaState.SB_SRC_ALPHA);

    as1.setDstFunction(AlphaState.DB_ONE);

   

    Cylinder cylinder = new Cylinder("cylinder1",15,15,1.0,10);

    cylinder.setRenderState(as1);                                          //make the cylinder transparent



    Cylinder c2 = new Cylinder("c2", 15, 15,0.2f,10);



    rootNode.attachChild(cylinder);

    rootNode.attachChild(c2);

2

The code you posted will not make the cylinder transparent by itself, you'll also need to apply a material state with a diffuse color that has an ambient less than 1 (like .5f)

3

renanse:

4

The Magic Word of the Day is render queues :slight_smile:



http://www.jmonkeyengine.com/jmeforum/index.php?topic=2954.0

5

Right, can you post a more complete test so we can all be on the same page?

6

  I got it.

  thanks

7

… and what do you do when an ortho (HUD) element needs to be transparent?

8

Normal object are drawn into a z buffer. With ortho there is no z-buffer (afaik). So, transparancy is not a problem. The second object is just drawn on top of the first, the third on top of the second and first, etc.

9

if you have a mixture of opaque and transparent, change the z order of the transparent ortho items so they draw after the opaque. Other than that, as llama said, there isn't a whole lot to worry about.