Problem with transparency of box

General Discussion Other

mathimathi

Problem with transparency of box

in General Discussion • Other • 7 months ago

I'm new to Processing, but I've been experimenting a bit and I've ran into somewhat of a strange problem. I was trying to build a simple house with windows, but as I continued building I noticed that only certain things are visible trough the window. I made a video to demonstrate my problem:

http://www.youtube.com/watch?v=KIXHWZF9bw8

Obviously, the black cube should be visible trough the window. I can't share the source code, since I'll be using this code for a school project and I don't want my classmates to copy it.

Thanks for taking the time to read/watch this. If you have any idea how to solve this, I'd love to hear it!

Replies(5)

asimes

Re: Problem with transparency of box

7 months ago

Can you post a highly reduced version that shows the minimal amount of geometry and from the point of view where the visual problem is occurring?

tfguy44

Re: Problem with transparency of box

7 months ago

Maybe this will help:

void setup(){
size(200,200,P3D);
noStroke();
}
void draw(){
background(128);
translate(width/2,height/2,0);
scale(2);
rotateY(map(mouseX,0,width,0,TWO_PI));
translate(20,-15,0);
fill(0,0,255,255);
box(20);
translate(-40,0,0);
fill(128,0,0,128);
box(20);
translate(40,30,0);
fill(128,0,0,128);
box(20);
translate(-40,0,0);
fill(0,0,255,255);
box(20);
}

I'm not sure why the order matters...

asimes

Re: Problem with transparency of box

7 months ago

It looks like Processing just isn't doing the transparency correctly in 3D.

amnon.owed

Re: Problem with transparency of box

7 months ago

This problem has been discussed quite a few times before, for example here.

This is an opengl problem related to depth and transparency.

The solution is depth sorting, but the convenience method to do this only exists in Processing 1.5.1.

mathimathi

Re: Problem with transparency of box

7 months ago

Thanks for your help! Indeed, using Processing 1.5.1 and adding "hint(ENABLE_DEPTH_SORT);" fixed the problem.

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