地形优化

The camera behavior in a project that utilizes a Landscape Terrain object plays an important role. A static camera implies a single load of data, provided all textures fit in the video memory. When the active camera significantly changes its position and orientation while unveiling unloaded areas, streaming may hit hard on performance. Therefore, performance and memory consumption should be considered and tuned for the final set of cameras and screen resolution of the target platform.使用 Landscape Terrain 对象的项目中的相机行为起着重要作用。如果所有纹理都适合视频内存，则静态相机意味着单个数据加载。当活动相机显着改变其位置和方向，同时揭示未加载区域时，流式传输可能会严重影响性能。因此，应根据目标平台的最终相机集和屏幕分辨率来考虑和调整性能和内存消耗。

For convenient profiling, you can animate the camera movement via Tracker and run animations for tests.为了方便分析，您可以通过 Tracker 为相机移动设置动画并运行动画进行测试。

It is recommended to use the Microprofile tool for detailed in-depth estimation for the performance of a Landscape Terrain object.建议使用 Microprofile 工具对 Landscape Terrain 对象的性能进行详细深入的估计。

Stages of Landscape Terrain operation in the output of the Microprofile tool.Microprofile 工具输出中的 Landscape Terrain 操作阶段。

By using the Rendering Performance Profiler, you can estimate the memory consumption.通过使用 Rendering Performance Profiler，您可以估计内存消耗。

Landscape Terrain-related section of the Rendering Performance Profiler output.Rendering Performance Profiler 输出的 Landscape Terrain 相关部分。

Hardware Recommendations硬件建议#

The number and density of different Landscape Layer Maps that define the look of the terrain at the current moment is an important factor — multiple blended layers with high resolution textures might make a significant performance drop. In most cases it is reasonable to combine multiple textures into a single one in a raster graphics editor.定义当前地形外观的不同 Landscape Layer Maps 的数量和密度是一个重要因素——具有高分辨率纹理的多个混合层可能会导致性能显着下降。在大多数情况下，在光栅图形编辑器中将多个纹理组合成一个是合理的。

注意

In contrast, you can use several Landscape Layer Maps that refer to the same .lmap asset without performance drop. You can create a Node Reference containing a Landscape Layer Map to propagate repetitive areas.相反，您可以使用多个引用相同 .lmap 资产的 Landscape Layer Maps，而不会降低性能。您可以创建一个包含 Landscape Layer Map 的 Node Reference 来传播重复区域。

The Current Data Density value for a Landscape Layer Map is calculated based on its spatial size and the resolution of base textures used. It's hard to miss that a decent high-detailed landscape would require a texture tileset of an extremely large resolution.Landscape Layer Map 的 Current Data Density 值是根据其空间大小和使用的基础纹理的分辨率计算的。很难错过一个像样的高细节景观需要一个非常大分辨率的纹理图块集。

最佳实践

Use base textures of Landscape Layer Maps to create a coarse look of the Landscape Terrain and refine the surface using details for high-detailed per-pixel quality.使用 Landscape Layer Maps 的基础纹理创建 Landscape Terrain 的粗糙外观并使用细节以获得高细节的每像素质量。

Also, the visibility of layers is taken into account — if a large Landscape Layer Map overlaps other layers (has a higher Order value), only its graphic data will be loaded and rendered.此外，还考虑了图层的可见性——如果大的 Landscape Layer Map 与其他图层重叠（具有更高的 Order 值），则只会加载和渲染其图形数据。

A schematic representation of several Landscape Layer Maps overlapping each other.
The one with the higher Order value overlaps the other ones and only its data will be loaded and visualized.几个 Landscape Layer Maps 相互重叠的示意图。
Order 值较高的那个与其他的重叠，只有它的数据会被加载和可视化。

Streaming is based on using previously loaded geometry to define the visible areas of terrain. There is no loaded geometry at the very world startup, so the system looks for a Landscape Layer Map that has the Culling flag enabled and loads preliminary low-level data of this layer. If your world contains several layers, one of which represents the basic shape of the terrain, while others are used as insets placed within the bounds of the base layer and having an insignificant height difference from it, it is recommended for you to disable Culling for insets and enable it for the base layer. This is how you can reduce load on CPU at the world startup.流式传输基于使用先前加载的几何图形来定义地形的可见区域。在世界启动时没有加载几何体，因此系统会查找启用了 Culling 标志的 Landscape Layer Map 并加载该层的初步低级数据。如果您的世界包含多个图层，其中一个代表地形的基本形状，而其他用作放置在基本图层边界内的插图，并且与它的高度差很小，建议您禁用 Culling插入并为基础层启用它。这是在世界启动时减少 CPU 负载的方法。

Each frame the Landscape Terrain system checks which tiles are to loaded and updated. Increase the Tiles Update Per Frame parameter to ensure that all necessary tiles are updated on time. However, if this value is too big, it may cause a performance drop during data streaming.Landscape Terrain 系统每帧都会检查要加载和更新哪些图块。增加 Tiles Update Per Frame 参数以确保按时更新所有必要的图块。但是，如果这个值太大，可能会导致数据流时性能下降。

The loading speed of chunks of graphic data depends on the Tiles Load Per Frame value. Higher values imply faster multi-threaded loading of tiles but more performance-consuming data streaming. Note that it is pointless to set this value higher than the Tiles Update Per Frame.图形数据块的加载速度取决于 Tiles Load Per Frame 值。较高的值意味着更快的多线程切片加载，但更消耗性能的数据流。请注意，将此值设置为高于 Tiles Update Per Frame 是没有意义的。

Thus, it is necessary to find a trade-off when tweaking these parameters.因此，在调整这些参数时有必要进行权衡。

Use the Landscape Terrain VT Streaming helper (or the render_show_landscape_terrain_vt_streaming 1 console command) to enable visualization of tiles being streamed. In this mode colored areas show the tiles that are currently being rendered in a lower resolution until the highest mip-level is loaded and rendered. The faster the colored tiles disappear, the better.使用 Landscape Terrain VT Streaming 帮助程序（或 render_show_landscape_terrain_vt_streaming 1 控制台命令）启用正在流式传输的切片的可视化。在此模式下，彩色区域显示当前以较低分辨率渲染的图块，直到加载和渲染最高 mip 级别。彩色瓷砖消失得越快越好。

The Landscape Terrain VT Streaming helperLandscape Terrain VT Streaming 助手

Cache缓存#

Run-Time Modification运行时修改#

The Landscape Terrain enables you to add up to 1024 details to a mask making it possible to create a pretty detailed and diverse look of the landscape. In terms of optimization, minimizing the number of details and textures is a way to faster rendering.Landscape Terrain 使您最多可以添加1024细节一个面具，可以创建一个非常详细和多样化的景观外观。在优化方面，尽量减少细节和纹理的数量是加快渲染速度的一种方式。

The textures of details are loaded at the world startup and kept in the video memory to be blended with the base textures of the Landscape Terrain when rendering. You can specify a lower resolution for the corresponding textures of all detail materials by tweaking the following parameters:细节纹理在世界启动时加载并保存在显存中，以便在渲染时与地形地形的基础纹理混合。您可以通过调整以下参数为所有细节材质的相应纹理指定较低的分辨率：

• Detail Albedo Texture Resolution
• Detail Height Texture Resolution
• Detail Additional Mask Texture Resolution

The final textures for tiles of the Landscape Terrain are written to the Virtual Texture components (Albedo, Normal and Height). Increase the Texture Memory Size value to ensure that the Virtual Texture provides enough capacity to store the loaded high-detail texture chunks.Landscape Terrain 的瓦片的最终纹理被写入虚拟纹理组件（Albedo, Normal 和 Height）。增加 Texture Memory Size 值以确保虚拟纹理提供足够的容量来存储加载的高细节纹理块。

The components of the Landscape Terrain Virtual Texture.Landscape Terrain 虚拟纹理的组件。

With a lower size the Virtual Texture requires less video memory but doesn't provide enough capacity to store all the required data resulting in poor performance, low detail level and fast flickering of the Landscape Terrain surface due to continuous reloading of tiles.由于尺寸较小，虚拟纹理需要较少的视频内存，但无法提供足够的容量来存储所有需要的数据，从而导致性能不佳、细节水平低以及由于连续重新加载瓷砖而导致景观地形表面快速闪烁。

Polygons of the Landscape Terrain surface are adaptively tessellated on the fly and displaced based on the Heightmap component of the Virtual Texture. The polygon mesh is split up to multiple levels of detail of various density depending on the distance from the camera. The Geometry settings provide much room for rendering optimization.Landscape Terrain 表面的多边形会根据虚拟纹理的高度图组件在运行中自适应地细分并移位。根据与相机的距离，多边形网格被分成不同密度的多个细节层次。 Geometry 设置为渲染优化提供了很大的空间。

Levels of Detail of tessellated geometry.镶嵌几何体的细节层次。

Pay attention to the following parameters:注意以下参数：

• With lower values of Geometry Progression less polygons are generated at a distance.使用较低的 Geometry Progression 值，在远处生成的多边形更少。
• By configuring the Geometry Polygon Size parameter you can define the minimum spatial size of polygons in case of excessive detail level.通过配置 Geometry Polygon Size 参数，您可以在细节级别过高的情况下定义多边形的最小空间大小。
• Geometry Subpixel Reduction parameter determines the minimum ratio of polygon size (in the screen space) to the area seen in the viewport. This parameter enables you to quickly decrease the number of polygons or simply remove too small polygons that are barely visible, in order to increase performance.Geometry Subpixel Reduction 参数确定多边形大小（在屏幕空间中）与在视口中看到的区域的最小比率。此参数使您能够快速减少多边形数量或简单地删除几乎不可见的太小多边形，以提高性能。
• Set a lower Visibility Distance to discard rendering of too remote polygons.设置较低的 Visibility Distance 以放弃渲染太远的多边形。

You can decrease the maximum allowed level of detail for the albedo, normal and height textures of the Landscape Terrain by increasing the Texel Size parameter. 您可以通过增加 Texel Size 参数来降低 Landscape Terrain 的反照率、法线和高度纹理的最大允许细节级别。

Decrease Target Resolution—the resolution of the screen buffer for the Landscape Terrain renderer—to gain more performance at a cost of visual quality.降低 Target Resolution（Landscape Terrain 渲染器的屏幕缓冲区的分辨率）以牺牲视觉质量来获得更高的性能。

You can also reduce the detail level of polygons facing the camera at oblique viewing angles (Detail Level By Angle) to optimize streaming load and memory consumption.您还可以降低以倾斜视角 (Detail Level By Angle) 面向相机的多边形的细节级别，以优化流加载和内存消耗。

Different mip-levels of landscape textures are used at different distances. Switch to the Low or Medium Texture Filtering quality to improve performance at a cost of a slightly visible edge between adjacent mipmap levels.在不同的距离处使用不同的 mip 级别的景观纹理。切换到 Low 或 Medium Texture Filtering 质量以提高性能，但代价是相邻 mipmap 级别之间的边缘略微可见。

Culling Optimization剔除优化#