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fan_vfx [2017/09/13 11:08] (current)
titterton created
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 +====== Fan - VFX ======
 +This section details the properties of the Fan object for SpeedTree Cinema.
 +
 +The direction and strength of the wind are indicated in the upper right corner of the [[tree_window|Tree Window]].
 +
 +=====Main=====
 +The properties in this group control wind quality and the enabled state.
 +
 +==Wind wizard...==
 +Press the button to launch the Wind Wizard. ​ This tool will set up the tree based on your answers to a few questions about its components.
 +
 +==Enabled==
 +Use this property to toggle wind on and off in the [[tree_window|Tree Window]].
 +
 +==Quality==
 +Controls the quality of the oscillation computations. ​ Use "​Draft"​ for faster previews while tuning and "​Production"​ for most exports.
 +
 +=====Settings=====
 +The properties in this group control high level wind settings.
 +
 +==Strength==
 +This property sets the strength of the wind. 0.0 corresponds to no wind, 1.0 corresponds to the highest wind.
 +
 +>​**Note**:​ The actual wind behavior is governed by how the properties below interpret the strength value. ​ It is possible to have some wind at 0.0 and no wind at all at 1.0, depending on how the properties are tuned.
 +
 +====Response Times====
 +These properties control how quickly the model responds to changes in wind strength and direction. ​ Large, heavy models should have large response times. ​ Small, light models should have short ones.  The idea that if a flower and an oak tree are placed under the influence of the same wind source, the flower should react more quickly to changes in that source than the oak tree does.
 +
 +==Strength==
 +Sets the response time for strength changes. ​ It is how long in seconds it would take the model to go from 0.0 behavior to 1.0 behavior.
 +
 +==Direction==
 +Sets the response time for direction changes. ​ It is how long in seconds it would take the model to react to a 180 degree change in wind direction.
 +
 +===== VFX Branch Motion =====
 +The properties in this group control branch motion. ​ In general, branch motion consists of bending in the direction of the wind and oscillating an amount governed by the turbulence properties (as pictured below). ​ The speed of the oscillation is controlled by the frequency properties.
 +
 +{{ ::​branches.jpg?​nolink |}}
 +
 +>​**Note**: ​ As with all wind curves, the left hand side of VFX Branch Motion curves correspond to minimum wind conditions and the right hand side corresponds to maximum wind conditions. ​ Current wind strength is indicated by the black line.
 +
 +====Scalars====
 +These values scale the corresponding affect by the value entered for each of the five branch wind groups.
 +
 +====Shared====
 +The properties in this group affect the entire model, essentially making it sway in the wind.  This is typically the slowest moving group and uses small values for bend and turbulence. ​ Large tree models typcially rely on this group for trunk bending so as not to waste a wind level on the trunk.
 +
 +==Bend==
 +This property controls how much the whole model will bend in the direction of the wind across all wind conditions.
 +
 +==Turbulence==
 +This property controls how much (the amount, not the speed) the whole model will oscillate around its bent over position as specified by "​Bend"​.
 +
 +==Frequency==
 +This property controls how fast the whole model will oscillate.
 +
 +==Twist==
 +This property controls how much the model twists around the global up vector.
 +
 +==Start==
 +This property designates the percentage up the tree where the "​Shared"​ wind effect begins. ​ Use this to prevent trunk motion near the bottom of large, stout models like oak trees by raising this value. ​ Small plants and thin trunks should use lower values, even 0.0.
 +
 +====Levels 1, 2, 3, and 4====
 +The properties in this group apply to geometry with the associated [[windvfx#​Editing Branch Wind|wind level]] as indicated by the number overlaid on the generators when wind is enabled. ​ Use the [[branch_generator#​Wind|wind weight profile curves]] on each branch generator to control how much each branch bends along its length.
 +
 +==Bend==
 +This property controls how much the longest branch at this level will bend in the direction of the wind across all wind conditions.
 +
 +==Turbulence==
 +This property controls how much (the amount, not the speed) the longest branch at this level will oscillate around its bent over position as specified by "​Bend"​.
 +
 +==Frequency==
 +This property controls how fast the branches at this level oscillate.
 +
 +==Flexibility==
 +This property control how much ripple will be seen during branch movement. ​ Use high values for this for flexible, soft stemmed plants and zero this value out for woody branches.
 +
 +==Independence==
 +This value controls how synchronized branch motion appears. ​ High values indicate that each branch moves independently and does not appear to be in unison with neighboring branches. ​ A value of 0.0 means all branches at this level move together. ​ Carefully chosen numbers here will reveal waves of wind rolling through the model while maintaining some chaotic motions. ​ This values is typically greater than 1.0 and less than 10.0.
 +
 +==Disable==
 +Check this box to disable all wind at this level. ​ Use this convenience to aid in tuning instead of disabling wind on multiple generators or setting their weights to 0.0.
 +
 +===== VFX Leaf Motion =====
 +The properties in this group control leaf motion. ​ Leaves bend in the direction of the wind and then oscillate around that position (similar to branches). ​ They also have an additional oscillation unrelated to the wind direction called "​Flutter"​.
 +
 +Leaves are assigned a group by one of their wind properties ([[batchedleaf_generator#​Wind|Batched leaves]] and [[leaf_mesh_generator#​Wind|leaf meshes]]). ​ Use this group setting to differentiate between leaves and other sorts of geometry like fruit during wind animation.
 +
 +>​**Note**: ​ As with all wind curves, the left hand side of VFX Leaf Motion curves correspond to minimum wind conditions and the right hand side corresponds to maximum wind conditions. ​ Current wind strength is indicated by the black line.
 +
 +====Scalars====
 +These values scale the corresponding affect by the value entered for each of the two leaf wind groups.
 +
 +====Groups 1 & 2====
 +These are the properties than control wind behavior for each group. ​ Because leaf animation is based on rotations, it is recommended that leaf wind weight profile curves be at or near max curves. ​ Any change in weight from the base to the tip of a leaf will be magnified in high wind conditions.
 +
 +==Bend==
 +This property controls how much the leaves will bend into the wind.
 +
 +===Turbulence===
 +These properties control how much the leaves will oscillate around the position determined by the "​Bend"​ property in this group. ​ Use turbulence to simulate the lower frequency, direction dependent leaf motion.
 +
 +==Frequency==
 +Controls how fast the leaves will oscillate.
 +
 +==Amount==
 +Sets the maximum amount of rotation for each oscillation.
 +
 +==Independence==
 +This value controls how synchronized leaf motion appears. ​ High values indicate that each leaf moves independently and does not appear to be in unison with neighboring leaves. ​ A value of 0.0 means all leaves move together. ​ Carefully chosen numbers here will reveal waves of wind rolling through the leaves while maintaining some chaotic motions. ​ This values is typically greater than 1.0 and less than 10.0.
 +
 +===Flutter===
 +The properties in the group control random rotations that are not based on wind direction. ​ Use "​Flutter"​ to add more chaos and high frequency motion into the leaf animation.
 +
 +==Frequency==
 +Controls how fast the leaves will oscillate.
 +
 +==Amount==
 +Sets the maximum amount of rotation for each oscillation.
 +
 +===== VFX Frond Motion =====
 +The properties in this group control frond wind animation. ​ There is currently a single frond group.
 +
 +====Group 1====
 +Fronds are constructed along "​ribs"​ growing perpendicular to the parent branch. ​ These properties control the motion of those ribs.
 +
 +>​**Note**: ​ This does not include the spine of the frond -- it only applies to the fronds themselves. ​ The spine must be animated by a branch level, even if the rendering of it is disabled.
 +
 +==Bend==
 +This property controls how much the fronds will bend into the wind.  ​
 +
 +===Turbulence===
 +These properties control how much the fronds will oscillate around the position determined by the "​Bend"​ property in this group.  ​
 +
 +==Frequency==
 +Controls how fast the fronds will oscillate.
 +
 +==Amount==
 +Sets the maximum amount of rotation for each oscillation.
 +
 +==Independence==
 +This value controls how synchronized frond motion appears. ​ High values indicate that each frond moves independently and does not appear to be in unison with neighboring fronds. ​ A value of 0.0 means all fronds move together. ​ Carefully chosen numbers here will reveal waves of wind rolling through the fronds while maintaining some chaotic motions. ​ This values is typically greater than 1.0 and less than 10.0.
 +
 +==Ripple==
 +This value controls how much ripple is allowed on individual frond. ​ Increase this value to make the frond ripple more like a flag and decrease it to make it look more like a waving metal sheet.
 +
 +=====Gusting=====
 +The properties in this group control the timing and strength of random wind [[windvfx#​Gusting|gusts]].
 +
 +==Enabled==
 +Toggles gusting on and off.  ​
 +
 +==Frequency==
 +Controls how often gusts can occur. ​
 +
 +==Strength==
 +Controls how much additional wind strength is added to the nominal wind strength during a gust.  Add variance to make each gust random. ​
 +
 +==Duration==
 +When a gust happens, this value controls how long it will remain active (in seconds). Use the variance to make each gust length random. ​
 +
 +====Response Scalars====
 +
 +==Rise==
 +This value scales how long it takes for a gust to reach its maximum value. Lower this value to increase the speed at which gusts impact the model.
 +
 +==Fall==
 +This value scales how long it takes for a gust to return to the nominal wind level. Lower this value to increase the speed at which the model returns to nominal wind conditions after a gust.