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Index › Programming Questions & Help › OpenGL and 3D Libraries › openGL, this transparency thing...
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openGL, this transparency thing... (Read 2213 times)
phling
openGL, this transparency thing...
Jan 11th, 2010, 8:40pm  
hello dear Processing forum,

i'm wondering if there is a fix for this issue where supposedly transparent planes are only properly transparent from one side, i.e. from certain angles they are opaque towards other objects except the background...

Nico loves banana.

Banana in front of Nico = all dandy.
Nico in front of banana = no proper transparency.
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jeffg
Re: openGL, this transparency thing...
Reply #1 - Jan 12th, 2010, 6:10am  
It was moving around so much I couldn't tell from the sketch link, but here were my first thoughts when reading the post.

Possibly lighting...?
try:
ambientLight(255, 255, 255, 0,0,0);

Blending...?
Maybe try cycling through blending options
http://74.125.47.132/search?q=cache:0QPN0etLW4MJ:boxofbooze.com/processing/glblend.html+space+junk+blend+example&cd=1&hl=en&ct=clnk&gl=us
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WWW  
phling
Re: openGL, this transparency thing...
Reply #2 - Jan 13th, 2010, 10:46am  
yep, the link you posted is perfect. thanks!
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jasongetsdown
Re: openGL, this transparency thing...
Reply #3 - Mar 15th, 2010, 2:22pm  
All I get from that link is a google cache of a domain squatter page. I'm having the same issue. Is there an up to date link?
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Stay Curious.
WWW gunarch  
jasongetsdown
Re: openGL, this transparency thing...
Reply #4 - Mar 15th, 2010, 2:41pm  
Using hint(ENABLE_DEPTH_SORT); gets transparency working correctly, but at the cost of performance. Also, for me at least, it introduced some funny little rendering errors. They look like regions that aren't shaded correctly that appear and disappear depending on the camera angle.
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Stay Curious.
WWW gunarch  
phling
Re: openGL, this transparency thing...
Reply #5 - Mar 21st, 2010, 4:14am  
here's the code from above: http://de.posi.to/codici/openGLblendmodesTest/openGLBlendModeTest2.pde

my personal favorite for most applications is this setting:
Code:
pgl = (PGraphicsOpenGL) g;
	gl = pgl.beginGL();
	gl.glDisable(GL.GL_DEPTH_TEST);
	gl.glEnable(GL.GL_BLEND);
	gl.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE);
	gl.setSwapInterval(1);
	pgl.endGL();


gives a nice "holographic" look by simply adding colors.

gl.setSwapInterval(1) is v-sync.
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