Texture transparency problem with P3D for Doom clone

Processing Coding Questions
1

Hello everyone!

I’m currently coding a “Doom” clone, using P3D. I’m not using any external library.
I’m having a weird artifact that happens when I’m using a masked texture. I’ve tried several methods to fix it, but to no avail :(. DISABLE_DEPTH_MASK suppresses the artifact, but then my sprite get sorted all wrong.

If anyone can point me in the right direction, I would really appreciate it! I’m so close to having a functional engine!
(disregard the “doom” face and soldier sprites, of course, they are just temporary assets I’m using…)

question1
question1.png760×424 125 KB

As you can see, eventhough the mask is working (see the feet of the soldier) it’s leaving a huge black (background color) artifact behind.

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2

question2
question2.png760×424 177 KB

Weirdly, when I walk around on the flip side, the artifact isn’t as bad (although still present)

3 Likes
3

Hi @luxregina first off, awesome project! Just from these screenshots alone I can tell you work really hard on this. Your issue seems to be a common problem https://forum.processing.org/two/discussion/26119/how-to-stop-edge-artifacts-when-using-a-spritesheet-textureatlas can you post a sample of your code? particularly where the mask texture is used

1 Like
4

This is the bit of code that draws my enemy : I’ve also rendered a video with the bug that can be viewed here > https://youtu.be/AI0y671POLo - thanks in advance!!! :slight_smile:

void drawItem(String type) {
    if (type == "pHealth") {
      lightFalloff(0.0001, 0.0001, 0.0001);
      if (lightsOn)pointLight(255, 0, 0, 0, 0, 0);
      drawCube(pHealth);
    }
    if (type == "crate") {
      drawCube(crate);
    }
    if (type == "enemy") {
      lightFalloff(0.0001, 0.0001, 0.0001);
      if (lightsOn)pointLight(180, 255, 0, 0, 0, 0);
      //blendMode(SCREEN);
      //hint(DISABLE_DEPTH_MASK);
      pushMatrix();
      rotateY(x);
      beginShape();
      texture(enemy);      
      //println(x);
      // +Z "front" face
      vertex(-64, -64, 0, 0, 0);
      vertex( 64, -64, 0, 64, 0);
      vertex( 64, 64, 0, 64, 64);
      vertex(-64, 64, 0, 0, 64);
      endShape();
      popMatrix();
      //hint(ENABLE_DEPTH_MASK);
      //blendMode(BLEND);
    }
  }

I’m using a PNG that should be transparent - I’ve also tried to mask it by using :slight_smile:

enemy = loadImage("enemy.png");
  enemy.mask(loadImage("enemy_mask.png"));

but to no avail… I should specify I’m using Processing 2.2.1

1 Like
5

@luxregina Are you using Raycasting to render this or using 3D objects?

6

Woooow ! Awesome project @luxregina :smiley: ! I think I know what is the solution to your problem :

hint(ENABLE_DEPTH_SORT);

here is an exemple showing the difference between ENABLE_DEPTH_SORT and DISABLE_DEPTH_SORT

 // Depth sorting example by Jakub Valtar 
// https://github.com/JakubValtar

void setup() {
  size(640, 720, P3D);
  colorMode(HSB, 100, 100, 100, 100);
    
  frameRate(60);
}
 
void draw() {    
    //beginRaw(PDF, "output" + frameCount + ".pdf");
    
  if (!mousePressed) {
    hint(ENABLE_DEPTH_SORT);
  } else {
    hint(DISABLE_DEPTH_SORT);
  }
    
  noStroke();
  
  background(0);
 
  translate(width/2, height/2, -300);
  scale(2);
    
  int rot = frameCount;

  rotateZ(radians(90));
  rotateX(radians(rot/60.0f * 10));
  rotateY(radians(rot/60.0f * 30));
 
  blendMode(ADD);
    
  for (int i = 0; i < 100; i++) {
    fill(map(i % 10, 0, 10, 0, 100), 100, 100, 30);
 
    beginShape(TRIANGLES);
    vertex(200, 50, -50);
    vertex(100, 100, 50);
    vertex(100, 0, 20);
    endShape();
 
    rotateY(radians(270.0f/100));
  }
    
  //endRaw();
  
  if (frameCount % 30 == 0) println(frameRate);
}

Dont worry about blendMode(ADD), its just to make it look better, you dont need it.

GG again for you project, I really like it :smiley: !

1 Like