Problems with PNG transparency and movement in the Z axis

Core Library Questions

julio33

Problems with PNG transparency and movement in the Z axis

in Core Library Questions • 2 years ago

I just noticed that the transparency of the .png files(and maybe other transparencies too) sometimes just won't work correctly if you move the .png thru the Z axis.

To show my point this is the code:

//////////////CODE

import processing.opengl.*;

PImage t1,t2;
int r=0;
float x=0;
void setup(){
//Asuntos de pantalla
size(400, 400, OPENGL);

t1=loadImage("t1.gif");

t2=loadImage("t2.gif");

}

void draw(){
translate(-250,-250,0);
background(0);
pushMatrix();
x+=0.05;
//rotateX(sin(x));
translate(0,0,100*sin(x));
image(t1,0,0);
//translate(100*sin(x)+cos(x),0,0);
image(t1,40,0);

//translate(tan(x),0,0);
image(t1,40,0);

popMatrix();

pushMatrix();
x+=0.05;
//translate(40*sin(x),0,0);
image(t2,20,20);
popMatrix();

}

///////////CODE

And the pair of images:

http://julio33.com/p5/t1.png
http://julio33.com/p5/t2.png

I think that when the blue image advance, it should show part the gray image, but it doesn't.

Also I try this with .gif, it's the same.

Thanks,
Julio

Replies(2)

amnon.owed

Re: Problems with PNG transparency and movement in the Z axis

2 years ago

The easiest way to get the behavior you are expecting is to put the following line in setup():

hint(ENABLE_DEPTH_SORT);

julio33

Re: Problems with PNG transparency and movement in the Z axis

2 years ago

That really solves the problem on Mac, but it seems that in XP doesn't(a friend told me). Also it seems that I could have performance issues because is some sort of hack or experimental.

But the answer is perfect to me, many thanks.

Julio

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