5 answers · asked · Lesson: Simulating the Launch Smoke · Course: Build and Animate a Low Poly Rocket in Blender 2.8 for Beginners

Some particles don't show up in rendered view

Hi, watching my simulation in the viewport shading, everything looks perfect. But when I render the frame (I render always single images, when doing animations), some particles don't show up at all. I baked the simulation, deleted it, re-baked it.  I have no clue what's going on. 

Using Blender 2.81 / Cycles GPU. I provided two screenshots, to illustrate the difference. The two pictures show the exact same frame.

Any hint is highly appreciated.

  • Strange! 

    If this is only one Particle System, then maybe it has to do with the Material; the Shader uses the lifetime of the Particles to determine how they look and as the oldest Particles do not render, they might be transparent???

    If your stuck, please upload your .blend file to a cloud service like Dropbox or so and post a link here.

    • That was one of the things that came to my mind. Unfortunately I dont't use a transparent node in this setup at all. But to be sure, I changed the material to use only  a simple diffuse shader.  Same effect. I will upload the blend file tomorrow. But thanks for the idea and the support.

    • So here is the link to the blend file: Rocket.blend

    • Well, this one is tricky!

      I haven't figured it out completely yet, but it has something to do with the keyframing of the Lifetime of the Particles.

      The Viewport doesn't seem to take that into account somehow, but the Render does. Hence the difference.

      With Keyframes:

      And without:

    • Hi, interesting. But animating the lifetime is what this is about. Maybe I try to use an older 2.79 version to check, if the behaviour differs.

      The viewport shows the expected result 

      Thanks for your effort.