This is a simple tutorial on simulating an nCloth cape. The cape is connected to a motion captured dancing character.
- Once you have your character and modeled cape, snap or translate vertices from the cape to the characters geometry. The vertices do not need to touch the character. You can position them anywhere that looks natural. Figure 2 shows the placement.
- Select all of the parts of the character. Choose nMesh>Create Passive Collider. This makes the characters geometry into an nRigid object (Figure 3).
- Select the cape and choose nMesh>Create nCloth. This makes the cape into an active nCloth object.
- Select the vertices you moved in step one and choose the character’s geometry. Select Constrain>Point to Surface. If your character has multiple parts, only select the vertices closest to each part and add separate constraints. In this example 3 different Point to Surface constraints were used
- The nCloth cape is now attached to the character. However before running the simulation, you need to establish the Space Scale. nCloth solves in meters therefore everything that is not modeled to meters must use a conversion. To figure out the conversion, measure your character from head to toe (Figure 4). Next, determine how big your character would be in the real world. In this example the character would be 6 ft in the real world or 182 cm. Since its scale matches the real world size we only need to convert from centimeters to meters. Select the cape and open its Attribute Editor. Find the nucleus tab. Click on it and open the Time Scale rollout. The default solver scale value is 1, meaning 1 x 1 Maya unit is equal to 1 meter. Change the solver scale to .01. Now the equation would read .01 x 1 Maya unit is equal to .01 meter or 1 cm. By changing the Space Scale to .01 you tell nCloth that everything connected to it is 1/100 smaller than a meter.
- Go back to the nCloth tab in the Attribute Editor. Assign it the tshirt preset. This preset is a bit to flexible for our cape. Change the Bend Resistance to 10.
- Now we are ready to see how it looks. Run the simulation. Figure05 shows the results.
- The cape isn’t keeping up with the speed of the motion capture. Open the nucleus node again and change the Time Scale to 2, increasing the speed of the simulation (Figure 6).
- The new simulation can be seen in Figure07.
- Almost there. The cape is moving better but now gets wrapped up and tangled. The quality of the solve itself needs to be improved. Once again go back to the nucleus node. This time open the Solver Attributes rollout. Increasing the Substeps and Max Collision Iterations prevents the cloth from getting tangled. For this example they have been increased to 6 and 8 respectively (Figure 8).
- The simulation is run again with improved results. Watch it now Figure09.
To learn how to take nCloth to the next level check out Maya Cloth for Characters.