物理优化

Set matching Collision Masks for those particular shapes, surfaces, and bodies that are expected to collide. If the masks do not match, shapes and bodies will simply ignore each other by going through.为预期会碰撞的特定形状Collision Masks，表面和实体设置匹配的 。如果蒙版不匹配，则形状和实体将通过相互忽略。

Collisions are calculated for a plane and a sphere while a box is ignored due to unmatching Collision Masks为平面和球体计算碰撞，但由于不匹配Collision蒙版而忽略了一个框

The Collision Mask of the sphere's physical shape球体物理形状的Collision蒙版	The Collision Mask of the box's physical shape盒子物理形状的Collision蒙版
The Collision Mask of the plane's surface平面的Collision蒙版	The Collision Mask of the ground's surface地面的Collision蒙版

In Unigine, you can set up filtering accurately by using the Exclusion Mask. This mask allows ignoring shapes with the matching exclusion masks regardless of their Collision Masks.在Unigine中，您可以使用排除掩码准确地设置过滤。此蒙版允许忽略具有匹配排除蒙版的形状，而不考虑其碰撞蒙版。

Surfaces that are not intended for physical interactions should have the Collision flag disabled. For example, a dashboard inside a cockpit would never take part in collision detection on the outside.不适用于物理交互的表面应禁用Collision标志。例如，座舱内的仪表板永远不会参与外部的碰撞检测。

Avoiding detection of undesired and unnecessary collisions is a basic way to reduce the amount of physical calculations.避免检测到不必要和不必要的冲突是减少物理计算量的基本方法。

Specify certain physicals that should affect only corresponding bodies by using the Physical Masks the same way as for collisions. On the image below, a Physical Wind object affects a cloth banner but not a sphere.通过使用 指定与碰撞相同的某些物理Physical Masks，它们仅会影响相应的物体。在下图中，一个Physical Wind对象会影响布料横幅，但不会影响球体。

A physical wind affects a cloth but not a sphere物理风影响布料但不影响球体

Physical mask of the cloth banner布标的Physical蒙版	Physical mask of the sphere球形的Physical蒙版
Physical mask of the Physical Wind object Physical Wind对象的Physical掩码

Intersection is a generic point of a specified area (or line) and an object. Calculation of intersection between a ray cast and a surface is fast and inexpensive and therefore sometimes can be used instead of computing collision. For example, calculation of collisions of car wheels with the ground can be simplified by using intersections. 交点是指定区域（或线）和对象的通用点。射线投射和曲面之间的相交的计算是快速且廉价的，因此有时可以代替计算碰撞而使用。例如，可以使用交叉点简化车轮与地面的碰撞的计算。

Although it is a programmatic approach only, it requires Intersection Masks to be set for filtering purposes.尽管它只是一种编程方法，但它需要设置 Intersection掩码 进行过滤。

Both physical shapes and surfaces have intersection masks.物理形状和曲面都具有交叉蒙版。

Physical shapes consisting of simple primitives make collision calculations easier while keeping performance high and accuracy acceptable. Therefore, it is recommended to approximate geometry with simple primitives (Sphere, Capsule, Cylinder, Box), which are faster and less memory demanding.由简单图元组成的物理 shapes 使得碰撞计算更容易，同时保持高性能和准确性。因此，建议使用简单的图元（ Sphere ， Capsule ， Cylinder ， Box ）对几何进行近似估算更快，内存需求更少。

Complex shapes, such as Convex Hull and a set of autogenerated convex hulls, should be selected for representing complex and composite geometry when simple shapes don't allow achieving the desired goals.当复杂形状和复合几何无法实现所需的形状时，应选择复杂形状，例如凸包和自动生成的凸包的集合期望的目标。

A car can be approximated using one complex shape and several simple shapes可以使用一个复杂的形状和几个简单的形状来近似汽车

At the same time you should keep the number of shapes as low as possible in order to avoid heavy calculations leading to the performance drop. Remember that a shape doesn't have to duplicate the mesh it approximates. Even though primitives are not precise, in most cases they provide acceptable results.同时​​，应将形状的数量保持为 low ，以避免繁琐的计算而导致性能下降。请记住，形状不必复制它近似的网格。即使基元不精确，在大多数情况下它们也可以提供可接受的结果。

Rough approximation is accurate enough粗略近似足够准确

The simpler geometry is used for surface collisions detection, the more performance will be gained.用于检测表面碰撞的几何形状越简单，将获得越多的性能。

If a mesh representing a physical obstacle has several levels of detail (LODs), the least detailed one is the most preferable for collision and intersection detection. Enable the Collision and Intersection options for this LOD and disable them for the other ones.如果代表物理障碍物的网格具有多个详细级别（LOD），则最不详细的级别最适合于碰撞和相交检测。对此LOD启用Collision和Intersection选项，对其他LOD禁用它们。

Use the lowest level of detail for intersections and collisions使用最低级别的相交和碰撞

Approximating collision shapes by using primitives is also a good practice. You can apply the following approach:使用基本体来逼近碰撞形状也是一种好习惯。您可以采用以下方法：

1. Ensure that the original node is not a Collider — check that Collision flag is disabled for its surfaces, bodies, and shapes. Since now it is not taken into account by collision detection.确保原始节点不是 Collider —检查是否已禁用Collision标志的表面，实体和形状。从现在起，碰撞检测就不再考虑它了。

2. Add a cylinder object to the scene by choosing Create -> Primitive -> Cylinder in the Menu Bar and cover the original mesh with the primitive.通过在菜单栏中选择Create -> Primitive -> Cylinder将圆柱对象添加到场景中，并用图元覆盖原始网格。

   

3. Make sure that the Collision option of the surface is enabled for the primitive node. 请确保已为原始节点启用了曲面的Collision选项。

4. Hide the visual representation of the primitive's surface. You can do it either by clearing its Viewport and Shadow masks or simply by setting its Max Visibility parameter to the negative infinity (-inf) — this ensures that the surface is not visible at any distance.隐藏基本体表面的视觉表示。您可以通过清除其Viewport和Shadow蒙版，或仅通过将其Max Visibility参数设置为负无穷大（-inf）来执行此操作，这可以确保在任何距离都看不到该表面。

   

   Now the detailed mesh provides only visual representation, while physical interactions are calculated for the primitive cylinder.现在，详细的网格仅提供视觉表示，而为原始圆柱体计算物理相互作用。