Announcement

Collapse
No announcement yet.

Intersecting Particles Problem

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Intersecting Particles Problem

    I have some simple cube particles in PFlow that collide on a flat surface so there are many that overlap one another. The cube particles are scaled in Z so they are for the most part, flat.

    I have an opacity map in a V-Ray material with a radial gradient applied to the particles mapped from the top down so the end result is that each square particle is transparent on the edges and opaque in the middle.

    Where the particles overlap, since they are co-incident, there are problems in the rendering with black splotches showing up. I found in the helpfile the secondary ray bias setting which does eliminate the black splotches but not the problem all together. The images below are TOP views looking straight down on the particles.

    This image shows the original problem:




    This image shows the effect of setting the secondary ray bias to a positive value. Notice that where the two particles overlap, the opacity is wrong:




    The scanline renderer renders these overlapping particles without problem as you can see in the last image. Notice that where the two particles overlap, the opacity is correct:



    How can I make V-Ray render these particles properly?

    Thanks!
    Sincerely,

    Mike Truly
    ----------------------------------------------------------------
    Truly Media
    http://www.trulymedia.com

  • #2
    This image shows the remaining problem even better:

    Sincerely,

    Mike Truly
    ----------------------------------------------------------------
    Truly Media
    http://www.trulymedia.com

    Comment


    • #3
      mike, whats your max depth set to in the global switches?
      Chris Jackson
      Shiftmedia
      www.shiftmedia.sydney

      Comment


      • #4
        jacksc02,

        I'll have to check setting that tommorrow as all systems are currently rendering another project. (I'm pretty sure that setting is at it's default as I don't recall messing with it).

        Thanks!
        Sincerely,

        Mike Truly
        ----------------------------------------------------------------
        Truly Media
        http://www.trulymedia.com

        Comment


        • #5
          You'll need to increase your secondary rays bias a bit, and maybe increase your max. transparency level.

          Best regards,
          Vlado
          I only act like I know everything, Rogers.

          Comment


          • #6
            Vlado,

            I tried that but it didn't fix the problem. I tried several Secondary Ray bias settings as well as Max Transparency Levels. Here's SRB: 1.0, MTL: 500



            Here's a simplified MAX8 file that shows not only this PFLOW intersecting particles problem but also the particle age map problem:

            http://www.trulymedia.com/issues/vra...e_problems.zip

            Thanks!
            Sincerely,

            Mike Truly
            ----------------------------------------------------------------
            Truly Media
            http://www.trulymedia.com

            Comment


            • #7
              I don't know that this is exactly related to the same thing but it might be so I thought I'd put this here.

              My intersecting PFLOW particles are used to create beach/ocean foam. As I am net-rendering, different resulting frames are having different artifacts in the area of these particles. The particles are set to receive shadows but NOT to cast shadows. Also the frame stamp info is intermittant on different frames:





              Thanks!
              Sincerely,

              Mike Truly
              ----------------------------------------------------------------
              Truly Media
              http://www.trulymedia.com

              Comment

              Working...
              X