6 Replies Latest reply on Jan 21, 2015 12:50 PM by joel_pau

    Snow Animation

    jonasxjonas

      I have found an Script to get Snowflakes in my Edge-Animation:

      http://www.heathrowe.com/edge/snowflakes/snowflakes.zip

       

      My Question:

      How can I get the Snowflakes above all the other objects?

      At the Moment they are only in the background, behind the other objects.

       

      Thanks for your help :-)

       

      Here is the Code that I use:

       

      
      
      //canvas init
      
      
      $('<canvas id="canvas"></canvas>').appendTo("#Stage");
      
      
      var canvas = document.getElementById("canvas");
      var ctx = canvas.getContext("2d");
      
      
      //canvas dimensions
      var W = window.innerWidth;
      var H = window.innerHeight;
      canvas.width = W;
      canvas.height = H;
      
      
      //snowflake particles
      var mp = 95; //max particles
      var particles = [];
      for(var i = 0; i < mp; i++)
      {
        particles.push({
        x: Math.random()*W, //x-coordinate
        y: Math.random()*H, //y-coordinate
        r: Math.random()*4+1, //radius
        d: Math.random()*mp //density
        })
      }
      
      
      //Lets draw the flakes
      function draw()
      {
        ctx.clearRect(0, 0, W, H);
      
      
        ctx.fillStyle = "rgba(255, 255, 255, 0.8)";
        ctx.beginPath();
        for(var i = 0; i < mp; i++)
        {
        var p = particles[i];
        ctx.moveTo(p.x, p.y);
        ctx.arc(p.x, p.y, p.r, 0, Math.PI*2, true);
        }
        ctx.fill();
        update();
      }
      
      
      //Function to move the snowflakes
      //angle will be an ongoing incremental flag. Sin and Cos functions will be applied to it to create vertical and horizontal movements of the flakes
      var angle = 0;
      function update()
      {
        angle += 0.01;
        for(var i = 0; i < mp; i++)
        {
        var p = particles[i];
        //Updating X and Y coordinates
        //We will add 1 to the cos function to prevent negative values which will lead flakes to move upwards
        //Every particle has its own density which can be used to make the downward movement different for each flake
        //Lets make it more random by adding in the radius
        p.y += Math.cos(angle+p.d) + 1 + p.r/2;
        p.x += Math.sin(angle) * 2;
      
      
        //Sending flakes back from the top when it exits
        //Lets make it a bit more organic and let flakes enter from the left and right also.
        if(p.x > W+5 || p.x < -5 || p.y > H)
        {
        if(i%3 > 0) //66.67% of the flakes
        {
        particles[i] = {x: Math.random()*W, y: -10, r: p.r, d: p.d};
        }
        else
        {
        //If the flake is exitting from the right
        if(Math.sin(angle) > 0)
        {
        //Enter from the left
        particles[i] = {x: -5, y: Math.random()*H, r: p.r, d: p.d};
        }
        else
        {
        //Enter from the right
        particles[i] = {x: W+5, y: Math.random()*H, r: p.r, d: p.d};
        }
        }
        }
        }
      }
      
      
      //animation loop
      setInterval(draw, 33);