[SOLVED] [LibGDX] Depth Testing in an FBO causes graphical issues

Newbie & Debugging Questions
#1

1662×1001 209 KB

Here’s the code for sorting out the FBO (the gist of it anyway)

gameFBO.begin();
Gdx.gl.glEnable(GL11.GL_DEPTH_TEST);
Gdx.gl.glClearColor(1f, 1f, 1f, 1f);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);

batch.draw(x);
batch.draw(y); // Maybe this is causing it (z fighting), but I've disabled all the draw calls except one and it's the same issue.

Gdx.gl.glDisable(GL11.GL_DEPTH_TEST);
gameFBO.end();

If this weird pattern looks familiar to someone, I’d appreciate the help!
An additional note: sometimes the white overlay is straight vertical lines separated by one pixel.

EDIT: Here’s the block for rendering the FBO

batch.begin();
batch.disableBlending();
batch.setColor(1, 1, 1, 1);
batch.setProjectionMatrix(camera.combined); // Orthographic, near = 0, far = 100
batch.draw(fboFlippedTexture, camera.position.x - fbo.getColorBufferTexture().getWidth() / 2, camera.position.y - fbo.getColorBufferTexture().getHeight() / 2, fbo.getColorBufferTexture().getWidth(), fbo.getColorBufferTexture().getHeight());
batch.flush();
batch.enableBlending();
#2

Another note: disabling depth testing causes the issues to go away, but I still need the depth buffer.
Here’s the initialization for the main FBO, notice it has depth enabled:
[icode]gameFBO = new FrameBuffer(Format.RGBA8888, viewportWidth, viewportHeight, true);[/icode]

#3

[s]I seem to have fixed it!
[icode]gameFBO = new FrameBuffer(Format.RGBA8888, viewportWidth, viewportHeight, true);[/icode]
to
[icode]gameFBO = new FrameBuffer(Format.RGB888, viewportWidth, viewportHeight, true);[/icode]

It could have been something with the alpha channel, either way… It’s cleaner now[/s]

Nope, broken again. Any help would be appreciated!

#4

Herp derp, I was drawing a framebuffer texture over the game’s framebuffer with depth test enabled… Disabled the depth testing while rendering that framebuffer texture and it all works!

#5

What you did was almost like rubber duck debugging…lol

Congrats on managing to resolve the issue yourself :slight_smile: In OpenGL, it’s pretty hard to debug and figure out what the heck you did wrong :stuck_out_tongue: