Hello! I'm ippuku_time, a GIS implementation support consultant.
This is the 23rd installment of the "5-Minute Guide to SuperMap iDesktopX" series. This time, we'll focus on performance optimization—a constant challenge in GIS projects that handle large volumes of data.
In particular, we'll reveal the secret to smooth 3D map performance by introducing caching techniques for 3D scenes.
1. Why performance optimization matters
The data handled by GIS—especially 3D city models, high-resolution aerial imagery, and large-scale terrain data—can be enormous. When such data is displayed directly, performance often depends heavily on PC specifications, which can lead to slow rendering, laggy navigation, and frustrating user experiences.
To achieve smooth operation and improve overall work efficiency, it is essential to use caching technology, which optimizes data specifically for fast visualization.
Figure: High-speed display of large-scale 3D city data using caching technology
2. "Scene cache"— the key to accelerating 3D scenes
One of the most effective ways to improve 3D scene performance is to create a scene cache. This technique converts original data that is slow to render—such as large BIM models or detailed terrain—into formats optimized for 3D scene display in advance.
Once a cache is created, SuperMap iDesktopX loads lightweight cache files instead of the original data, resulting in dramatically faster display performance.
iDesktopX supports different types of scene caches depending on the data type:
(1) Image cache (*.sci3d)
Used for raster data such as wide-area aerial photographs and satellite imagery. It adopts a pyramid structure based on zoom levels, enabling fast and efficient rendering.
(2) Terrain cache (*.sct)
A cache format designed for rapidly displaying terrain data such as DEMs (Digital Elevation Models) in a true 3D environment.
(3) Model cache / Vector cache (.scv, .scp)
These caches support high-speed rendering of 3D models (e.g., buildings) and 2D vector data (points, lines, and polygons) in 3D scenes. They are especially essential when working with large-scale 3D city models, such as Project PLATEAU.
3. Generate a cache for the entire scene
A particularly useful feature of iDesktopX is “Generate cache for the entire scene.” This function converts all layers loaded in the current 3D scene—terrain, imagery, models, and more—into optimal cache formats in a single operation.
Operation steps:
1️Open the 3D scene for which you want to create caches.
2️In the Workspace Manager, right-click the scene name and select "Generate Scene Cache…"
3️In the dialog box, specify the cache output location, resolution levels (LOD), and other settings.
4️Click "Generate" to create cache files for all scene layers at once.
Summary
In this article, we introduced performance optimization, with a focus on scene caching technology for efficiently handling large-scale 3D data. As GIS projects become larger and more detailed, the ability to properly create and manage caches becomes a critical skill that can directly impact project success.
With its support for multiple data types and powerful cache generation capabilities, iDesktopX provides strong support for building a smooth, stress-free 3D GIS environment.
In the next installment, Part 24: "Customize Your GIS! An Introduction to Custom Development," we'll explore how to customize the iDesktopX interface and extend its functionality using Python or Java. Stay tuned!
For source and sample code: https://supermap-japan.blogspot.com/2025/09/243didesktopx.html
