Technical Direction 1

Cloth Simulation

Here are the steps to simulate a Nimmie scene:

• Set the Cloth_ExpandWaistBand pose to 100% at frame 0 of the chor or action.
• Check frame 0 carefully, to be sure that Nimmie’s dress isn’t touching any of the deflectors. If they are touching, fix them by reposing that frame with muscle or any other technique.
• At frame 1 of the chor, set the Plugin Properties.SimCloth.Scale property of the Cloth_WaistBand group to 75%. This will shrink the waist band down, and grip Nimmie’s waist without the need for attached groups, which have problems with penetrating her body.
• Set the collision radius property of the chor to 0.5cm. It can be larger to prevent penetrations due to spline curvature, but then everything must be that far apart at the beginning too.
• Set the substeps to 16, and the subdivisions to 0. These are Plugin.SimCloth properties of the chor. For fast movements, this can be set higher, for slower movements it can be less. I have had better luck when the steps don’t change dynamically.
• Set the Time range. (only if something less than the whole chor length needs simulated)
• Add the Deflector Material to any additional needed deflectors, like the ground. You may need to embed the model which you are adding the deflector to, unless it should be a deflector in every scene. Embedding is a little dangerous, since the embedded model will never get another update when the original model changes.
• Then choose the Chor/Plugin/"SimCloth Simulate" menu, and watch and wait…
• If there are problems, see my cloth tech talk for some of the answers.
• When you are happy with the results, the Muscle motion from frame 0 to frame 99 can be deleted from the timeline to save space, since the motion there is never seen in the shot anyway.

Note
Nimmie Aimee’s apron will not currently simulate and is going to require some serious ingenuity, or a new feature to get it right for the final shots of this film. More about this later.

Dynamic Simulations

Dynamic Constraints

Some characters in TWO have Dynamic Constraints as part of their rig. Scarecrow's belt and hat, Woots belt and backpack straps, are two examples.

Here is the current procedure to prepare a scene for rendering so the the dynamics will be correct.

1. Make as many models inactive as you can (frame 0 on). Usually this will be all but one. This makes the simulation faster.
   1. It is a good idea to first make a pws filter on the word "Active", and note any objects that are currently set to inactive anywhere in their choractions.
2. Set the rigs dynamic settings to be uniform from frame 0 to the end of the scene.
   1. Usual location: pose slider panel, Animation_Controls, Dynamics. Woot has belt_dynamics and backpack outside of Dynamics.
3. Turn off Draw Particles/Hair unless hair needs to be simulated too.
4. Simulate Spring Systems with these steps.
   1. First make sure the choreography's length property ends at or just after the scene's render range. Otherwise if the length is to long it will simulate longer than you need (sometimes a lot longer).
   2. Create and activate a new choreography action for each model with dynamics in the simulation. This is to isolate the simulation data.
   3. Name the new choraction "Dynamics".
   4. Go to frame 0 and right click the choreography and choose Simulate Spring Systems.
   5. Move the new choraction above the existing choraction (so that the existing one will remain the active one when the choreography is loaded.
5. Check the animation from ten frames before scene start to ten frames past scene start (usually 90 to 110).
   1. If the animation jumps this might cause the simulation to jump. The animation before scene start may need to be adjusted.
   2. Resimulate if needed.
6. If there are two or more characters to simulate, make the current one inactive and activate the next one. Repeat the process.
7. When all characters are simulated, remove any active channels you created from the model's choractions, and restore any preexisting active states.
8. Save the choreography.