## 2 Modeling
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameters** & **Range** & **Type** & **Introduction** \\ \hline maximumScreenSpaceError & (0,+\(\infty\)) & float & The maximum screen space error used to drive level of \\  & & & detail refinement. \\ baseScreenSpaceError & [0,+\(\infty\)) & float & When skipLevelOfDetail is true, the screen space error that \\  & & & must be reached before skipping levels of detail. \\ skipScreenSpaceError & (0,+\(\infty\)) & float & When skipLevelOfDetail is true, a multiplier defining the \\  & & & minimum screen space error to skip. \\ maximumMemoryUsage & [0,VRAM] & float & The maximum amount of memory in MB that can be used \\  & & & by the tileset. \\ cullRequestsWhileMoving & [0,+\(\infty\)) & float & Multiplier used in culling requests while moving. Larger is \\  & Multiplier & & more aggressive culling, smaller less aggressive culling. \\ progressiveResolutionHeight & (0,0.5) & float & This can help get a quick layer of tiles down while full \\  & & & resolution tiles continue to load. \\ dynamicScreenSpaceError & [0,1) & float & This controls the camera distance at which the \\  & & & dynamicScreenSpaceError optimization applies. \\ foveatedConeSize & [0,1] & float & Determination of the central area \\ foveatedMinimumScreenSpace & [0,+\(\infty\)) & float & Improved screen space error factor for edge tiles \\  & & & \\ ErrorRelaxation & [0,+\(\infty\)) & float & Delayed loading time after the camera stops moving \\  & & & Larger values cause lower resolution tiles to load, \\ dynamicScreenSpaceErrorFactor & [0,+\(\infty\)) & float & improving runtime performance at a slight reduction of \\  & & & visual quality. \\ skipLevels & [0,5) & int & Used in conjunction with skipLevels to determine which \\  & & & tiles to load. \\ skipLevelOfDetail & true/false & boolean & Determines if level of detail skipping should be applied \\ immediatelyLoadDesiredLevel & & & during the traversal. \\ OffDetail & true/false & boolean & When skipLevelOfDetail is true, only tiles that meet the \\  & & & maximum screen space error will ever be downloaded \\  & & & Whether the siblings of visible tiles are always downloaded \\  & & & during traversal \\ cullWithChildrenBounds & true/false & boolean & Whether to cull the parent tile using the concatenation of \\  & & & the child tile’s minimal envelope \\ cullRequestsWhileMoving & true/false & boolean & Not requesting tiles that may not be used due to \\  & & & camera movement \\  & & & Prioritize loading of leaf nodes \\  & & & Use lower resolution tiles far from the camera. This reduces \\  & & & the amount of data loaded and improves tileset loading \\  & & & time with a slight drop in visual quality in the distance. \\  & & & Used to prioritize the loading of tiles in the center of \\  & & & the screen \\  & & & preloadFlightDestinations \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Cesium 3 DTiles rendering parameters. have the condition constraint that variable A is true for variable B to take effect [15]. The constraint equations are as follows:  
\[\left\{ \begin{aligned} x_{j}^{L}\leq x_{j}\leq x_{j}^{ LI},j=1,2,\ldots,20\\ x_{12}\to x_{2},x_{11},x_{13},x_{14}\\ x_{18}\to x_{6},x_{10}\\ x_{19}\to x_{7},x_{8},x_{9}\end{aligned} \right. \tag{2}\]  
where \(x_{j}\) represents the jth-dimension vector of the solution, i.e., the value of the jth parameter to be optimized; \(x_{j}^{L}\) and \(x_{j}^{LI}\) represents the upper and lower bounds of the jth-dimension vector, respectively; \(x_{j1}\to x_{j2}\) represents that \(x_{j2}\) is valid only if \(x_{j1}\) is true. Definition 3 (rendering time): Definition _Time(X)_ denotes the rendering time of the 3 DTiles model under solution \(X\).