trails on object build and fade question

I am trying to animate a simple graph. The shape begins as one large triangle. The triangle then breaks apart into four smaller triangles. These triangles drift upwards, and each spins slowly to a different position, before all come together as one large tirangle again.

As they drift up, however, they need to leave some sort of trail. The trail needs to appear as they raise up into the air behind them, then dissappear when they come to rest.

The animation of each object is simple, but does anyone have any suggestions how I night simulate a trail effect?

Somwhere there’s a sequence editor tutorial that has wireframe cubes leaving trails of afterimages. Basically you composite several layers of the same animation, each with an offset and other effects. I’ll try to find the link.


Here is the seq. editor tutorial for wireframe cubes with glowing trails. It’s a bit dated (from the NaN days!) but the basic principles still apply.

The effort is much appreciated, CD38. I took a look, and it helped a great deal. The problem (it’s minor tho) is that the echo works in 2D - much like After Effects “echo” function (which I’ve now opted for after animating the moving triangles in blender). I have a camera pan that moves vertically, so the trails need to fall downwards. The illusion will suffice, for now, tho.

What about Motion Blur?


Well… motion blur won’t give the right illusion. The camera moves up as the triangle float into their new formation.

My brief has changed. The triangles now need to rise up, revealing that they are extruded prisms. Now, I was thinking of using curves to model the prisms, but these triangles need to twist and rotate, as if dancing around each other. The best way I thought of doing this is to duplicate each triangle mesh, set “dupliframes” on it, make duplis real, join meshes, and fill in each face one by one until I have the completed prism. I would then attach a blend texture to it, that reveals its alpha over time via a null object parented to the texture’s alpha channel.

I was wondering if there is an easier way?