====== Wind ======

The wind within the 3ds Max plugin behaves as it was defined in Cinema. Strength and direction are variable within Max.

Wind works with Max's [[https://knowledge.autodesk.com/support/3ds-max/learn-explore/caas/CloudHelp/cloudhelp/2017/ENU/3DSMax/files/GUID-3CF078AB-7956-41E4-87D8-025EA962FEA5-htm.html|Wind Space Warp]] object, both directional and spherical. The default strength value of 1.0 results in a strong wind. The useful range for SpeedTree is between 0.0 and about 3.0.

Multiple wind space warps attached to a single SpeedTree object will result in an aggregate wind effect.



===== Pre-Roll =====

By default, the wind system begins with a strength of zero and ramps up to the set strength. By using a pre-roll of around 10 seconds, the wind system is put into a steady-state, bypassing the ramp up so that the wind will be blowing at or near the desired strength by the first frame. If a start-up animation is desired, set this value to 0.0.

===== Optimizing =====

The wind object has several attributes that can help optimize workflow when the wind computation load gets too high:

  * **Suspend Updates:** If there are 50 unique 5M-tri trees in a scene tied to a wind source and you drop the wind strength from 75% to 50%, it could take two minutes or longer for them to update. If you enable Suspend Updates, the wind computation will be bypassed until it is re-enabled.

  * **Use Fast Noise:** This is the same as the production/draft noise toggle in the Modeler. It can reduce wind computation by 30-50%.