Nice challenge… I would approach in a brute force way by using path animation with multiple nulls, apply a linear interpolation L(0,100) to the nulls and copy a few rocks onto the nulls (instances). Then apply jitter to the curve, The rotation on the rocks I would apply on the rocks themselves before they are instanced as with so many copies any chance of seeing a pattern would be minimal.
Then I would copy paste the curves as many times required and change the radius of the curve. Surely will be heavy but you could do this in 20 minutes. If you have to exactly mimic a torus then you could first extract the curves although then you would have to copy paste for ages… may be a hybrid by using a shape key to the curves to match the curves extracted? Jordi Bares jordiba...@gmail.com On 11 Feb 2014, at 19:23, Matt Lind <ml...@carbinestudios.com> wrote: > An artist came to my desk yesterday asking how to do what I felt was a simple > task, but after getting 80% through it I ran into a speed bump realizing it > needed custom scripting or other advanced tools to fully resolve to > satisfaction. I had to give him a procedure that was ‘good enough’. This > problem has multiple solutions, but I am curious how others would solve it: > > The problem: > > Artist must create an asteroid belt around a planet. The asteroids are > likely 2D sprites which must face the camera and tumble as they orbit, but > could be 3D objects as well. Asteroids must vary in size, shape, and > animation speed (linear as well as rotational). Asteroids cannot collide > with anything. Movement is generally slow – like a screen saver for your > computer desktop. Asteroid positions are jittered within the belt. > > The question: > > Dispersing objects into a ring is fairly straightforward through a number of > techniques, but how do you apply the random jitter to the object positions? > > The rules: > > - Cannot use ICE > - Cannot use custom scripts, custom operators, or shaders. > - Must only use tools out of the box that a junior or staff level > artist would know how to use. > - Must be able to create the asteroid belt, from scratch to > completion, in less than 30 minutes – and be iteration friendly to react to > art director feedback. > - Ideally, the belt could be made a child of the planet in > encompasses so it can be reoriented with respect to changes in the planet’s > size/shape/tilt/orbit. > - Final output must be able to exist with full integrity on its own > in a vacuum. Cannot not have dependencies on custom code, external assets, > or special case logic. > - Asteroid belt fits within the default grid as seen in the scene > camera. Think torus with diameter 40 SI units, and cross section of roughly > 3 SI Units diameter > > > Ready…..GO! > > > > > Matt