User Tools

Site Tools

Trace:

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

leaf_mesh_generator [2017/09/07 15:09]
 leaf_mesh_generator [2021/04/27 09:19] (current)
Line 1: Line 1:
 +====== Leaf Mesh Generator ======
 +{{:leafmesh.jpg?100 |{{:leaf_gen_v8.png?100|}}
 +
 +The Leaf Mesh generator is responsible for generating leaves based on [[kcmaterials|materials]] and [[kcmeshes|mesh]] assets.  Leaf Mesh generators (along with [[batchedleaf_generator|Batched Leaf]] generators) are the primary mechanism by which [[kcseasons|season]] transitions occur.
 +
 +===== Generation =====
 +The [[generation_properties|properties]] in this group control how many leaves are generated and where they are placed.
 +
 +===== Forces =====
 +The properties in this group control how forces affect the nodes created by this generator.  Forces affect only the orientation, not the position, of leaf meshes.
 +
 +== Allow Forces ==
 +When enabled, all forces that are checked will act on the generator.
 +
 +== Forces ==
 +Each [[kcforces|force]] in the scene has an entry here.  Check the box next to the name to enable the force for this generator.  The value set here is multiplied by the strength of the force before being applied to the branch.  The profile curve controls have no effect on leaves.
 +
 +>**Note:** Click on the force name to edit the force's properties.
 +
 +===== Random Seeds =====
 +Properties that have [[toolvariance_editor|variance]] are given random values based on a seed value in this group.  Vary the seeds in this group to randomize only the properties associated with the seed type. 
 +
 +== Randomize All ==
 +Randomizes the value for all seeds used to compute this generator. 
 +
 +===== Leaves =====
 +The properties in this group control the type, size, and initial placement of the leaf nodes.
 +
 +== Size ==
 +This property sets the size of the leaf nodes.  By default, mesh assets are treated as unit meshes and then scaled by this amount when placed on the model.
 +
 +== Use Actual Size ==
 +When enabled, the size parameter is ignored and the mesh is used at exactly the size at which it was modeled.
 +
 +== Flip ==
 +When enabled, randomly selected leaf nodes are flipped over the Y-axis.
 +
 +== Weld ==
 +When enabled, leaves will be placed directly on the skin of their parent (as opposed to being anchored on their spine).
 +
 +== Cross ==
 +When enabled, leaves are rotated so that they are perpendicular to the original leaf placement. This is a shortcut for creating crossed, intersecting meshes that have the same position.
 +
 +== Fix Winding ==
 +When enabled, the face winding of the polygons in the final mesh is adjusted to match the direction of the surface normals.  This correction is applied after vertex deformation and lighting adjustments.
 +
 +==== Type ====
 +The properties in this group specify the materials and meshes for the leaf.  Meshes must be assigned to the material on the [[kcmaterialsassetsbar|Material Bar]] to be used on the leaf.  Materials are chosen based on their weights and [[kcseasons|season]] settings.
 +
 +== Material ==
 +This property specifies a named material from the [[kcmaterialsassetsbar|Material Bar]]. If "None" is selected or the chosen material has no assigned mesh, a simple square will be used as placeholder geometry.
 +
 +== Mesh ==
 +Use this property to choose a particular mesh from the material asset or allow it to pick randomly ("Any"), the first mesh on the asset ("Primary"), or any mesh but the first ("Not primary").
 +
 +== Weight ==
 +Sets probability that a node will receive this material (this weight ÷ sum of all weights).
 +
 +==== Resolution ====
 +The properties in this group influence the resolution of the mesh.
 +
 +== Size Increase % ==
 +This curve controls the increase in the size of the leaf nodes as the [[kcresolution|resolution]] changes.  It is often desirable to increase the size of the leaves at lower resolutions to make up for a lower number of leaves.
 +
 +== Mesh LOD ==
 +This curve sets which mesh version ("High", "Medium" or "Low" detail on the mesh asset) is used based on the active resolution. 
 +
 +== Mesh LOD Offset ==
 +When set to a value other than 0, the mesh currently assigned will go up or down in mesh resolution ("High", "Medium" or "Low" detail on the mesh asset). Use this property (especially in conjunction with its parent curve) to adjust mesh resolution throughout the model.
 +
 +>**Note:** "Mesh LOD" and "Mesh LOD Offset" both require meshes assigned in at least two of the three [[kcmeshes|mesh asset]] LOD slots.
 +
 +===== Local Orientation =====
 +The properties in this group are the first stage of orienting the leaf.  The orientation actions are performed in the order in which the properties are listed.
 +
 +== Unification ==
 +Uses the anchor to orient itself "out" before the rest of the orientation adjustments are performed.  The "Out" direction is considered to be the vector from the anchor point through the node's attachment point. Anchor point placement options are as follows:
 +
 +^Global|The anchor point is located where the node's highest ancestor hits the ground.|
 +^Deep|The anchor point is the base of a node very near (and sometimes exactly on) the root of the node's ancestors.|
 +^Intermediate|The anchor point is somewhere in the middle of the node's ancestors.|
 +^Local|The anchor point is very near where the node is attached.|
 +^None|No anchor point is computed, and no unification is done.|
 +
 +== Sky Influence ==
 +Controls how much the leaves point toward the sky. Higher numbers result in the 'Z' axis of each mesh pointing straight up.
 +
 +== Fold ==
 +Rotates leaves up or down around the parent's growth direction.
 +
 +== Align ==
 +Rotates the tip of the leaves toward or away from the parent's growth direction.  Use this property to point leaves in the direction the parent is growing.
 +
 +== Face ==
 +Spins the leaves around their stem so that their "up" vector points in the direction of the parent's growth.  Use this property to make the leaves face out relative to their parent.
 +
 +>**Note:** Interval and Phyllotaxy generation modes work best with these properties.  These modes give each leaf an idea of which side they're on.  Doing so makes a positive value for "Align," "Face," and "Fold" all work the same, regardless where the leaf was generated.
 +
 +===== Sensitivity =====
 +The properties in this group control the second stage of leaf orientation.
 +
 +==== Parent ====
 +Parent sensitivity refers to orienting the leaf based on where it is positioned relative to its ancestors.
 +
 +== Amount ==
 +Sets the amount that the bottom of the leaf is turned to face the point set by Anchor.
 +
 +==Anchor==
 +This property picks a spot on one of the leaf's ancestors according to the following options:
 +
 +^Global|The anchor point is located where the node's highest ancestor hits the ground.|
 +^Deep|The anchor point is the base of a node very near (and sometimes exactly on) the root of the node's ancestors.|
 +^Intermediate|The anchor point is somewhere in the middle of the node's ancestors.|
 +^Local|The anchor point is very near where the node is attached.|
 +^None|No anchor point is computed, and no parent sensitivity is added.|
 +
 +==Sky==
 +Rotates the mesh around its central axis to get its "Z" axis as close to up as it can.  Think of it as the leaves rotating around their stem to face the light.
 +
 +===== Final Adjustments =====
 +These edits are applied to the leaf meshes as a group after Local Orientation and Sensitivity are computed.
 +
 +== Up ==
 +Rotates each mesh around its local X axis.
 +
 +== Right ==
 +Rotates each mesh around its local Y axis.
 +
 +== Out ==
 +Rotates each mesh around its local Z axis.
 +
 +===== Deformation =====
 +The properties in this group alter the shape of the leaf mesh. It is important to remember that these properties work best when there are enough vertices in the mesh to reveal the changes.
 +
 +>**Note:** Using these properties on low-resolution meshes can produce undesirable results.  You should always have at least one vertex near the center of the mesh for the best results.
 +
 +==Fold==
 +Folds both sides of the leaf, lengthwise along the Y-axis of the mesh. A negative value bends down, while a positive value bends up. 
 +
 +==Curl==
 +Curls the leaf around the mesh's X-axis.
 +
 +==Twist==
 +Twists the leaf around the mesh's Y-axis.  The farther away a vertex is from the X-axis, the more it is rotated.
 +
 +==== Vertex ====
 +The properties in this group perform a noise-based deformation of each vertex in the mesh.
 +
 +== Amount ==
 +This property controls the amount of noise applied to each vertex.
 +
 +== Noise ==
 +This value controls the tightness of the noise pattern. Higher values result in more localized deformations.
 +
 +== Seed ==
 +Vary this parameter to randomize the noise pattern.
 +
 +====Scale====
 +The properties in this group scale the mesh.  The scale is performed in each leaf's local orientation.
 +
 +==X==
 +Scales the mesh by this amount in the X-axis.
 +
 +==Y==
 +Scales the mesh by this amount in the Y-axis.
 +
 +==Z==
 +Scales the mesh by this amount in the Z-axis.
 +
 +===== Lighting =====
 +The properties in this group modify the vertex normals to change the lighting behavior of the mesh.
 +
 +>**Note:** These properties are not typically necessary for high detail VFX models but they can significantly improve the lighting on meshes that represent [[atclusters|clusters]] of leaves in real-time models.
 +
 +==Smooth==
 +Use this property to compute smooth normals based on the average face normals at each vertex after the deformations have been computed.  A value of zero means no smoothing, a value of 1.0 means completely smoothed normals.  The other lighting adjustments in this group are applied after smoothing.
 +
 +==== Parent Puffiness ====
 +== Amount ==
 +Value scale that controls how much the normals on each individual leaf should face "out" depending on the assigned anchor point. A value of 1.0 makes each normal line up with the vector that goes from the anchor through the vertex.
 +
 +>**Note:** Click on a leaf with hints on to see the "Parent puffiness" vectors.  
 +
 +==Anchor==
 +This property picks a spot on one of the leaf's ancestors according to the following options:
 +
 +^Global|The anchor point is located where the node's highest ancestor hits the ground.|
 +^Deep|The anchor point is the base of a node very near (and sometimes exactly on) the root of the node's ancestors.|
 +^Intermediate|The anchor point is somewhere in the middle of the node's ancestors.|
 +^Local|The anchor point is very near where the node is attached.|
 +^None|No anchor point is computed, and no parent puffiness is added.|
 +
 +== Puffiness ==
 +After all normal adjustments have been performed, this value “sphere-izes” the normals around the center of the mesh, making the geometry have a more puffy appearance.
 +
 +==Unify==
 +This property causes all vertex normals to point in the average direction of all of the vertex normals.  Use this property to align the normals to help localize specular effects.
 +
 +==== Adjustments ====
 +The properties in this group rotate the normals of each leaf without rotating the geometry.  These properties are commonly used when creating [[atclusters|clusters]].
 +
 +>**Hint:** Apply variance to these properties to make leaves in a cluster appear jumbled when lit in the final model.
 +
 +== Up ==
 +This property rotates vertex normals around the local X axis.
 +
 +== Right ==
 +This property rotates vertex normals around the local Y axis.
 +
 +== Out ==
 +This property rotates vertex normals around the local Z axis.
 +
 +===== Wind =====
 +The properties in this group influence how leaves are animated in wind simulations.
 +
 +==Scalar==
 +Use this property to scale how much the leaf moves during wind simulations.  The amount and frequency of motion are set on the [[fan|Fan]] object.  The left-hand side of the profile curve corresponds to the pivot point.  The right-hand side corresponds to the vertex farthest away.
 +
 +>**Note:** The left-hand side of the profile curve must be zero to avoid disconnecting from the parent.
 +
 +==Group==
 +In many wind styles, multiple wind groups are available.  Use this property to specify which group the leaves belong to.  The most common use of this feature is to have separate animation parameters for leaves and fruit.
 +
 +==Seed==
 +Vary this parameter to randomize wind characteristics.
 +
 +==Lock to parent==
 +When enabled, leaf mesh stay attached to their parent during wind animation but do so by sacrificing their own, independent motion.
 +
 +===== Growth =====
 +The properties in this group control how the model behaves during animated growth.  In general, you create the model in the fully grown state and use these properties to control how it gets there.
 +
 +== Speed Scale ==
 +The speed at which a leaf will grow is set on the [[tooltimeline|Timeline Bar]]. Use this property to scale that value. The profile curve scales the speed relative to the leaf's total growth time. For example, ease in and out of the growth animation by using an "S-curve."
 +
 +== Smoothing ==
 +Leaves can be oriented either based on the current state of their parent (0.0 smoothing), the final state of their parent (1.0 smoothing), or anywhere in between. Increase this value to prevent wild leaf motion during growth. This is especially useful for leaves growing off of a twisted or gnarled parent. 
 +
 +==== Transitions====
 +== Size ==
 +This curve control how the size increases over the course of the leaf's growth time.
 +
 +== Orientation ==
 +This value controls how much to rotate the leaf about its local X axis at the start of its growth period.  The profile curve controls how it transitions to the final orientation.  The rightmost point of the profile curve must be at 1.0 to match the model as it appears when growth is disabled.
 +
 +== Curl ==
 +Adds additional curl to the leaf at the start of the growth.  The profile curve sets how much of the additional curl is added during the growth cycle of the leaf.
 +
 +== Fold ==
 +Adds additional fold to the leaf at the start of the growth.  The profile curve sets how much of the additional fold is added during the growth cycle of the leaf.
 +
 +==== Timing ====
 +== Style ==
 +Sets the conditions under which the leaf will start growing. The Start % property works according to the option selected here. Options include:
 +
 +^In Place | The leaf will start growing exactly when the parent is long enough to reach its starting point in the fully grown model. "Start %" has no effect. This style makes the animation appear to trace out the model.|
 +^Parent | The growth of this leaf will be based on the growth of the parent. A Start % of 0.0 means start when the parent starts, 1.0 means start when the parent ends. |
 +^Parent's Start and End | The growth of this leaf will start and stop in perfect synchronization with its parent. Start % has no effect.|
 +
 +== Start % ==
 +Causes leaves to start early (0.0) or late (1.0) according to the "Style" property as described above.
 +
 +== Offset ==
 +The start frame is shifted by a constant number of frames (negative means earlier, positive means later). This value is best used to “jumble up” start times of neighboring leaves. 
 +
 +>**Note:** It is almost never a good idea to go negative with this value (leaves can't grow earlier than the structure will allow). A good practice is to have a value of something like 10 and a variance of 10 as well. That way the earliest any leaf will start is when it was supposed to, but some will be delayed.
 +
 +====Noise====
 +The properties in these groups add noise to the growth animation to provide a more organic effect.
 +
 +===Wobble===
 +==Amount==
 +Controls how much noise is applied when bringing the orientation into its final position.
 +
 +>**Note:** The final value for the profile curve must be 0.0 in order for the model to exactly match its correct final position.
 +
 +==Frequency==
 +Increases or decreases the frequency of the noise pattern used for orientation.
 +
 +===Speed===
 +==Amount==
 +Controls how much noise is applied to the speed at which the leaf reaches its final position.
 +
 +>**Note:** The final value for the profile curve must be 0.0 in order for the model to exactly match its correct final position.
 +
 +==Frequency==
 +Increases or decreases the frequency of the noise pattern used for speed.
 +
 +==Seed==
 +Change this value to vary the noise pattern.
 +
 +===== Season =====
 +The properties in this group control how leaves transition in the [[kcseasons|seasons]] system.
 +
 +== Start Offset ==
 +Leaf transitions are determined by looking up season curves based on the position of the season slider.  This value provides an offset on that curve lookup.  Use variance on this property to randomly shift when neighboring leaves begin their transition.
 +
 +== Time Scale ==
 +Scales how fast time passes relative to a single leaf.  Higher values make leaves transition faster.
 +
 +== Drop Time ==
 +Controls how long the leaf will remain attached.  A leaf can drop no matter what material is assigned.
 +
 +== Droop ==
 +Use this value to make leaves droop as they transition.
 +
 +== Curl ==
 +Use this value to make leaves curl as they transition.
 +
 +== Fold ==
 +Use this value to make leaves fold as they transition.
 +
 +==== Fallen ====
 +When "Show dropped leaves" is checked on the Season Slider, the properties in this group influence the behavior of leaves on the ground (or ground mesh).
 +
 +== Ground duration ==
 +The amount of time the leaves stay on the ground before disappearing.
 +
 +== Spread ==
 +Controls how far from the point directly under the tree the leaf may travel before hitting the ground.
 +
 +== Flatten ==
 +Determines the amount of deformation removal ("Season:Curl" and "Season:Fold") applied to the fallen leaves.
 +
 +== Jumble ==
 +Randomizes the orientations of leaves on the ground.
 +
 +== Slope Limit ==
 +If you have a force mesh applied to the leaf generator, fallen leaves will adhere to it instead of the ground.   In that circumstance, use this property to keep leaves from gathering on slopes.
 +
 +===== Dynamic LOD =====
 +The properties in this group control the [[kclod|LOD]] behavior of the leaves.
 +
 +==Weight==
 +Use this value to increase or decrease the likelihood that leaves in this generator will survive the LOD process (vs. leaves in other generators).  Use the parent curve to target specific areas of the model.
 +
 +==Scale Factor==
 +Leaves that survive the LOD process grow to fill the vacated space.  The amount is set in the [[tree_generator#Dynamic LOD|Tree generator's LOD section]].  This property scales that amount for leaves in this generator.
 +
 +==Mesh Index==
 +This curve controls which mesh LOD (if present) is used for each LOD state.  The left side of the curve corresponds to the highest LOD.  The right side corresponds to the lowest LOD.
 +
 +===== Vertex Color =====
 +The properties in this group control how vertex colors are computed.
 +
 +>**Note:** "Vertex colors" must be enabled on the [[tree_generator#Compute Flags|Tree]] generator for these properties to work.
 +
 +====Red====
 +The properties in this group control how the red component of the color is computed.
 +
 +==Style==
 +This property controls how the red portion of the color is computed from the following options:
 +
 +^Set | Sets the color directly using the "Value" property (parent colors are ignored). |
 +^Offset from parent | The "Value" property is added to the vertex color inherited from the parent. |
 +
 +==Value==
 +This property adds to, subtracts from, or directly sets this color component.
 +
 +====Green====
 +The properties in this group control how the red component of the color is computed.
 +
 +==Style==
 +This property controls how the red portion of the color is computed from the following options:
 +
 +^Set | Sets the color directly using the "Value" property (parent colors are ignored). |
 +^Offset from parent | The "Value" property is added to the vertex color inherited from the parent. |
 +
 +==Value==
 +This property adds to, subtracts from, or directly sets this color component.
 +
 +====Blue====
 +The properties in this group control how the red component of the color is computed.
 +
 +==Style==
 +This property controls how the red portion of the color is computed from the following options:
 +
 +^Set | Sets the color directly using the "Value" property (parent colors are ignored). |
 +^Offset from parent | The "Value" property is added to the vertex color inherited from the parent. |
 +
 +==Value==
 +This property adds to, subtracts from, or directly sets this color component.
 +
 +====Mesh Asset====
 +The properties in this group control how vertex colors stored in the [[kcmeshes|mesh asset]] are combined with the computed vertex colors.
 +
 +==Style==
 +This property controls how mesh asset vertex colors are used from the following options:
 +
 +^Interpolate | The "Contribution" value is used to blend from the computed to color (0.0) to the color stored in the asset (1.0). |
 +^Add | The "Contribution" value is used to scale the mesh asset vertex color and the result is added to the computed vertex color. |
 +
 +==Contribution==
 +This value sets how much influence the mesh asset vertex color has on the final vertex color.
 +
 +===== Collision =====
 +The properties in this group influence how leaves in this generator interact with the [[toolcollision|collision]] system.
 +
 +== Style ==
 +Use this property to set how the leaves behave during collision computations from the following options:
 +
 +^Everything | Leaves in this generator collide with each other and all other leaves.|
 +^Ignore Siblings | Leaves in this generator ignore siblings but collide with everything else.|
 +^Knock out Others Only | Leaves in this generator cannot be removed, but they can eliminate leaves in other generators.|
 +^Nothing |These leaves do not participate in collision computations.|
 +
 +== Take parent ==
 +When enabled, if a leaf in this generator is removed, its parent is also removed.  Use this option to take away twigs supporting leaves that are removed.
 +
 +== Ignore parent==
 +Check this box to have leaves ignore their parent when checking collisions.  This is useful when you're certain that the base of the leaf will frequently collide but the tips will not.
 +
 +== Also remove descendants ==
 +If this leaf is eliminated during collision computations, checking this box will ensure that any of its children (and their children and so on) are also eliminated.  This feature is useful when leaf meshes are used to represent image-based branches and have other leaves as children.
 +
 +== Weight ==
 +When leaves collide, the one with the higher weight wins.  Use this property to set the weight.
 +
 +== Pivot Threshold ==
 +This property sets how far away from pivot (as a percentage of size) a collision has to happen in order to count.  Use this property to eliminate unwanted removals of leaves anchored near each other.
 +
 +== Sphere Threshold ==
 +When using spherical leaf collision tests, this value scales the size of the spheres used during the test.  Spheres are initially sized based on leaf size.
 +
 +===== Lightmap =====
 +The property in this group affects the influence leaves in this generator have on the lightmap.
 +
 +>**Note:** Not all versions of the Modeler support lightmap UV computation.
 +
 +==Weight==
 +Use this property to increase or decrease the importance of this generator's leaves in the lightmap -- in relation to the lightmap weight of all other objects -- before lightmap packing is determined.  Note that your Weight value may not be honored exactly or may get so large as to exhibit unexpected results.  Use "Tools->Reset lightmap scalars" to go back to default values for the whole model.