世界样条图

• The WorldSplineGraph class article to learn how to manage world spline graphs via APIWorldSplineGraph类文章，学习如何通过API管理世界样条图
• The SplinePoint class article to learn how to manage spline graph points via APISplinePoint类别文章，了解如何通过API管理样条图点
• The SplineSegment class article to learn how to manage spline graph segments via APISplineSegment类别文章，了解如何通过API管理样条图段
• C++ sample for the WorldSplineGraph class illustrating how to manage spline graphs and generate geometry along the graph segments: source/samples/Api/Nodes/WorldSplineGraphWorldSplineGraph类的C ++示例，说明如何管理样条图以及沿图段生成几何： Source / samples / Api / Nodes / WorldSplineGraph
• Samples illustrating use cases of the WorldSplineGraph node included in the Samples suite:
  • world_spline_graph/roads - roads created on the terrain surfaceworld_spline_graph/roads - roads created on the terrain surface
  • world_spline_graph/ropes - ropes, chains, and cablesworld_spline_graph/ropes - ropes, chains, and cables
  world_spline_graph/roads - roads created on the terrain surfaceworld_spline_graph/ropes - ropes, chains, and cables样本说明WorldSplineGraph的用例Samples套件中包含的节点：
  • world_spline_graph/roads - roads created on the terrain surfaceworld_spline_graph/roads-在地形表面上创建的道路
  • world_spline_graph/ropes - ropes, chains, and cablesworld_spline_graph/ropes-绳索，链条和电缆

New points are added to the spline graph by cloninng existing ones. To add a new point do the following:通过克隆现有点将新点添加到样条图中。要添加新点，请执行以下操作：

1. Select the World Spline Graph.选择World Spline Graph。
2. Select the desired point, which you wish to clone (Move manipulator will appear).选择要克隆的所需点（将出现“移动操纵器”）。
3. Press Ctrl + D on the keyboard (a new point will be created).在键盘上按Ctrl + D（将创建一个新点）。
4. Use the Move manipulator to position you new created point.使用“移动”操纵器来放置新创建的点。

To adjust position of a point do the following:要调整点的位置，请执行以下操作：

1. Select the World Spline Graph.选择World Spline Graph。
2. Select the desired point (Move manipulator will appear).选择所需的点（将出现“移动操纵器”）。
3. Use the Move manipulator as you would do to move a node.使用移动操纵器，就像移动节点一样。

You can also adjust the position of the selected point via the Spline Points section of the Parameters tab:您还可以通过Parameters选项卡的Spline Points部分来调整所选点的位置：

Tangents control the curvature of the spline segment. To adjust tangent at a point do the following:切线控制样条线段的曲率。要调整一点的切线，请执行以下操作：

1. Select the World Spline Graph.选择World Spline Graph。
2. Select the desired point (Move manipulator will appear).选择所需的点（将出现“移动操纵器”）。
3. Select the desired tangent (in case the selected point is shared by multiple segments, several tangents will be displayed for it). As you select a tangent the Move manipulator appears next to it.选择所需的切线（如果所选点被多个线段共享，则将为其显示多个切线）。选择切线时，其旁边将显示“移动”操纵器。
4. Use the Move manipulator as you would do to move a node (the form of the corresponding segment will change).使用移动操纵器，就像移动节点一样（相应段的形式将改变）。

Up vector controls orientation of nodes placed along the spline segment. To adjust tangent at a point do the following:上矢量控制沿样条线段放置的节点的方向。要调整一点的切线，请执行以下操作：

1. Select the World Spline Graph.选择World Spline Graph。
2. Select the desired point (Move manipulator will appear).选择所需的点（将出现“移动操纵器”）。
3. Select the desired UP vector (in case the selected point is shared by multiple segments, several UP vectors will be displayed for it).选择所需的UP向量（如果所选点被多个线段共享，则将为其显示几个UP向量）。
4. Switch to Rotate manipulator and use it to adjust the desired angle as you would do to rotate a node (the orientation of nodes placed along the corresponding segment will change).
   注意

   You'll be able to see the effect only when a node is assigned to the corresponding segment.You'll be able to see the effect only when a node is assigned to the corresponding segment.
   You'll be able to see the effect only when a node is assigned to the corresponding segment.切换到“旋转操纵器”并使用它来调整所需的角度，就像旋转节点一样（沿着相应线段放置的节点的方向会改变）。
   注意

   You'll be able to see the effect only when a node is assigned to the corresponding segment.仅当将节点分配给相应的线段时，您才能看到效果。
5. Use the Move manipulator as you would do to move a node (the form of the corresponding segment will change).使用移动操纵器，就像移动节点一样（相应段的形式将改变）。

Sometimes it might be necessary to merge certain points (e.g. to close a spline). To merge two or more points into one do the following:有时可能需要合并某些点（例如，关闭样条线）。要将两个或多个点合并为一个，请执行以下操作：

1. Select the World Spline Graph.选择World Spline Graph。
2. Select points you want to merge with a region selection tool or one-by-one while holding the Shift key pressed.按住Shift键，选择要与区域选择工具合并的点或一对一地选择点。
3. Right-click on a point you want to merge selected ones into and choose Merge To This Point.右键单击要合并所选点的点，然后选择Merge To This Point。
4. All points will be merged into one shared by the segments, to which the merged points belonged.所有点将合并为合并的点所属的线段共享的一个。

To delete point(s) of the spline graph do the following:要删除样条图的点，请执行以下操作：

1. Select the World Spline Graph.选择World Spline Graph。
2. Select point(s) you want to delete with a region selection tool or one-by-one while holding the Shift key pressed.按住Shift键，使用区域选择工具或一对一地选择要删除的点。
3. Press the Del key.按Del键。

注意

Deleting points will automatically delete all segments, to which these points belong.删除点将自动删除这些点所属的所有线段。

To add a new segment to the spline graph do the following:要将新线段添加到样条图，请执行以下操作：

1. Select the World Spline Graph.选择World Spline Graph。
2. Select the starting point for the new segment to be added (Move manipulator will appear).选择要添加的新段的起点（将显示“移动操纵器”）。
3. Press and hold the Shift key and use the Move manipulator to position the ending point of the new segment.
   注意

   • To create a straight segment, you should drag the manipulator in the direction of the tangent at the starting point.To create a straight segment, you should drag the manipulator in the direction of the tangent at the starting point.
   • The new added segment uses all settings (assigned nodes, placement modes and parameters) of the previous one.The new added segment uses all settings (assigned nodes, placement modes and parameters) of the previous one.
   To create a straight segment, you should drag the manipulator in the direction of the tangent at the starting point.The new added segment uses all settings (assigned nodes, placement modes and parameters) of the previous one.按住Shift键，然后使用“移动”操纵器定位新线段的终点。
   注意

   • To create a straight segment, you should drag the manipulator in the direction of the tangent at the starting point.要创建直线段，应在起点处沿切线方向拖动操纵器。
   • The new added segment uses all settings (assigned nodes, placement modes and parameters) of the previous one.新添加的细分受众群使用上一个细分受众群的所有设置（分配的节点，放置模式和参数）。

You can also clone segment(s) by selecting them and moving with the Shift key pressed, or pressing Ctrl + D and placing the clone with the Move manipulator.您也可以通过选择分段并按Shift键移动来对其进行克隆，或者按Ctrl + D并使用“移动”操纵器放置克隆。

To delete segment(s) of the spline graph do the following:要删除样条图的线段，请执行以下操作：

1. Select the World Spline Graph.选择World Spline Graph。
2. Select segment(s) you want to delete with a region selection tool or one-by-one while holding the Shift key pressed.按住Shift键，使用区域选择工具或一一选择要删除的段。
3. Press the Del key.按Del键。

注意

If you delete a segment that enters into a junction, the latter will cease to function properly.如果删除进入路口的路段，路口将停止正常运行。

To assign a source node to selected segment(s) do the following:要将源节点分配给选定的段，请执行以下操作：

• Select the desired segments(s).选择所需的段。
• Click Add Node in the Parameters tab.在Parameters选项卡中单击Add Node。
• In the window that opens, select the required node and click OK.
  注意

  Source nodes to be assigned to segments and points are stored in *.node files. The node file should contain a Static Mesh, Skinned Mesh, or Projected Decal as a root node.Source nodes to be assigned to segments and points are stored in *.node files. The node file should contain a Static Mesh, Skinned Mesh, or Projected Decal as a root node.
  Source nodes to be assigned to segments and points are stored in *.node files. The node file should contain a Static Mesh, Skinned Mesh, or Projected Decal as a root node.在打开的窗口中，选择所需的节点，然后单击OK。
  注意

  Source nodes to be assigned to segments and points are stored in *.node files. The node file should contain a Static Mesh, Skinned Mesh, or Projected Decal as a root node.要分配给线段和点的源节点存储在*.node文件中。节点文件应包含Static Mesh, Skinned Mesh或Projected Decal作为根节点。

For each of the source nodes assigned to the selected segment(s) the following settings are available for adjustment via the Parameters tab:对于分配给所选段的每个源节点，以下设置可通过Parameters选项卡进行调整：

Node	Path to a *.node file containing a source node.包含源节点的*.node文件的路径。
Forward Axis	Defines which axis of the source node is to be oriented along the spline.定义将沿样条线定向源节点的哪条轴。
Placement Mode	Type of objects to be generated. One of the following: Stretch - a single source node instance is stretched along the segment. 注意 This mode is the most performance-friendly.This mode is the most performance-friendly. This mode is the most performance-friendly.Stretch - a single source node instance is stretched along the segment. 注意 This mode is the most performance-friendly.This mode is the most performance-friendly. Tiling - multiple instances of the source node are placed along the segment. The number of instances is determined by the sizes of the segment and the source node and the value of the Gap parameter.Tiling - multiple instances of the source node are placed along the segment. The number of instances is determined by the sizes of the segment and the source node and the value of the Gap parameter. Adaptive - a combination of the previous two resulting in multiple instances of the source node placed along the segment. Some of these instances may be stretched depending on segment's curvature.Adaptive - a combination of the previous two resulting in multiple instances of the source node placed along the segment. Some of these instances may be stretched depending on segment's curvature. Stretch - a single source node instance is stretched along the segment. 注意 This mode is the most performance-friendly.This mode is the most performance-friendly. This mode is the most performance-friendly.Tiling - multiple instances of the source node are placed along the segment. The number of instances is determined by the sizes of the segment and the source node and the value of the Gap parameter.Adaptive - a combination of the previous two resulting in multiple instances of the source node placed along the segment. Some of these instances may be stretched depending on segment's curvature.要生成的对象的类型。以下之一： Stretch - a single source node instance is stretched along the segment. 注意 This mode is the most performance-friendly.This mode is the most performance-friendly. This mode is the most performance-friendly.Stretch-沿该段拉伸单个源节点实例。 注意 This mode is the most performance-friendly.此模式是最性能友好的。 Tiling - multiple instances of the source node are placed along the segment. The number of instances is determined by the sizes of the segment and the source node and the value of the Gap parameter.Tiling-源节点的多个实例沿线段放置。实例数由段和源节点的大小以及Gap参数的值确定。 Adaptive - a combination of the previous two resulting in multiple instances of the source node placed along the segment. Some of these instances may be stretched depending on segment's curvature.Adaptive-前两个的组合，导致沿该段放置源节点的多个实例。这些实例中的某些实例可能会根据线段的曲率进行拉伸。
Adaptive Threshold	Determines how much a source node's instance can be stretched in the Adaptive placement mode to cover the whole length of the segment. 注意 Available for Adaptive placement mode only.Available for Adaptive placement mode only. Available for Adaptive placement mode only.确定在Adaptive放置模式下可以将源节点的实例拉伸多少，以覆盖该段的整个长度。 注意 Available for Adaptive placement mode only.仅适用于Adaptive放置模式。
UV Tiling	Enables tiling of the source node's textures.启用源节点纹理的平铺.
Gap	Defines the gap (in units) between the adjacent instances on the source node for the Tiling placement mode. 注意 Available for Tiling placement mode only.Available for Tiling placement mode only. Available for Tiling placement mode only.为Tiling放置模式定义源节点上相邻实例之间的间隔（以单位为单位）。 注意 Available for Tiling placement mode only.仅适用于Tiling放置模式。

To assign a source node to selected point(s) do the following:要将源节点分配给选定的点，请执行以下操作：

• Select the desired point(s).选择所需的点。
• Click Add Node in the Parameters tab.在Parameters选项卡中单击Add Node。
• In the window that opens, select the required node and click OK.
  注意

  For a junction point to behave properly an ObjectMeshSkinned node should be assigned, and the number of its bones should correspond to the number of spline segments connected to this point.For a junction point to behave properly an ObjectMeshSkinned node should be assigned, and the number of its bones should correspond to the number of spline segments connected to this point.
  For a junction point to behave properly an ObjectMeshSkinned node should be assigned, and the number of its bones should correspond to the number of spline segments connected to this point.在打开的窗口中，选择所需的节点，然后单击OK。
  注意

  For a junction point to behave properly an ObjectMeshSkinned node should be assigned, and the number of its bones should correspond to the number of spline segments connected to this point.为一个交界处为使点正常运行，应分配一个ObjectMeshSkinned节点，其骨骼的数量应与连接到该点的样条线段的数量相对应。

For each of the source nodes assigned to the selected point(s) the following settings are available for adjustment via the Parameters tab:对于分配给选定点的每个源节点，以下设置可通过Parameters选项卡进行调整：

Node

Path to a *.node file containing a source node.包含源节点的*.node文件的路径。

Variant

There is a number of possible variants for a junction. This slider enables you to choose the one that fits best. 注意 This parameter affects only the source nodes representing junctions (ObjectMeshSkinned).This parameter affects only the source nodes representing junctions (ObjectMeshSkinned). This parameter affects only the source nodes representing junctions (ObjectMeshSkinned).有许多可能的变体交界处。使用此滑块可以选择最合适的一个。 注意 This parameter affects only the source nodes representing junctions (ObjectMeshSkinned).此参数仅影响表示结点（ObjectMeshSkinned）的源节点。

Junctions交界处#

Due to the nature of the mesh, there will be visual artifacts connected with the float precision, if World Spline Graph is exported to a very big object (around 10,000 m from the origin to either side). We recommend splitting such big objects to smaller ones.由于网格的性质，如果将 World Spline Graph 导出到非常大的对象（从原点到两侧大约 10,000 m），则会出现与浮点精度相关的视觉伪影。我们建议将这些大对象拆分为较小的对象。

A problem may also arise if World Spline Graph, though being not very big, is located very far from the origin (around 10,000 m and further). In this case we advise exporting it to FBX without storing pivot (the Save root transform option should be disabled), or resetting the World Spline Graph position to origin before exporting it to Mesh.如果 World Spline Graph 虽然不是很大，但距离原点很远（大约 10,000 m 甚至更远），也可能会出现问题。在这种情况下，我们建议在不存储枢轴的情况下将其导出到 FBX（应禁用 Save root transform 选项），或者在将其导出到 Mesh 之前将 World Spline Graph 位置重置为原点。