# Determination of Point-to-Point 3D Routing Algorithm Using LiDAR Data for Noise Prediction
## 3 Methodology
### Building Corner Extraction Step 1 to Step 3
#### 3.3.2 Route around the Sides (Step 10 to Step 19)
Distances are stored in an array for an array1 in \(D\) and an array2 in \(C\) shown in (Figure 10a,b). \[D=[\text{d1},\text{d2},\text{d3},\text{d4},\text{d5},\text{d6},\text{d7},\text {d8}]\]  
where \(d\) = distance between and the \(I\) = \([x_{i},y_{i},z_{i}]\). \[C=[\text{c1},\text{c2},\text{c3},\text{c4},\text{c5},\text{c6},\text{c7},\text {c8}]\]  
where \(c\) = distance between and the \(I\) = \([x_{i},y_{i},z_{i}]\). Step 16: A cutting plane (XY perpendicular to Z) is drawn between the source and destination, so that intersection points of buildings with planes is calculated, and the intersection points are stored in an array. Figure 11a shows the selection of inlier buildings with the help of the buffer region \"abcd\" in the previous image. The inlier buildings are based on the ground as (A1, A2, A3, A4), (B1, B2, B3, B4), (D1, D2, D3, D4), (E1, E2, E3, E4), and (F1, F2, F3, F4). Step 17: Consider the _Array_1 and calculate the intersection height array. After calculating the intersection height array, choose the maximum \(dH\) value out of the array \(D\). For the \(dH\), find a corresponding \(IH\) and make a line between source and the \(IH\) point. Check whether any building intersects in between; if any building intersects, create an array for  
Figure 10: (a) “abcd” shows the buffer region to select inlier and outlier buildings. The intersection points i1, i2, i3, i4, i5, i6, i7, and i8 were calculated from the intersection of the XZ plane between source and destination with the buildings. In this, the region “abfe” is considered and the distance from the right-side building points to the intersection points as (\(d1\) = distance from B1 to \(i1\)) similarly from B3, D1, D3, E1, E3, F1 to i2, i3, i4, i5, i6, i7, and i8 are d2, d3, d4, d5, d6, d7, and d8 where S is source and D is the destination. (b  
intersecting building array (_IBA_). If there exists an intersection, keep on adding in _IBA_. After this, take the last element of _IBA_, create a line with the source, and again check for intersection and update _IBA_. Repeat the process till the _IBA_ is null. Then, when the last found element of _IBA_ is connected to the _IH_ point of _dH_ again, repeat the above process until the pointer reaches the _dH_ point. Step 18: After reaching the _dH_ point, make a line between _dH_ and the destination. Check further for the intersection buildings and stores in IBA and repeat step 21 until the pointer reaches the destination point. The entire route for array1 is _Source-1-2-Destination_, shown in Figure 10(c). Figure 10(c) mentions \"abcd\" is the buffer region to select inlier and outlier buildings. Route from _Source(S)-1-2-Destination(D)_ is the left side route for region \"_abfe_\", where 1 and 2 (_iD1_ and _iD3_) shows the intersection point with the cutting plane \"LMNO\" between the source and destination. The source is denoted by \"_S_\" and destination is denoted by \"_D_\". Step 19: Repeat steps 17 and 18 for the Array2 and form a route. The entire route for _Array2 is Source-3-4-Destination_ shown in Figure 10(d). The entire route around the sides is shown in Figure 10(e). Routes for the project area of an RGIPT campus for both right and left sides (Included in Supplementary Section S2.3.2). Figure 10(d) mentions \"abcd\" is the buffer region to select inlier and outlier buildings. Route from _Source(S)-3-4-5-Destination(D)_ is the right-side route for region \"cdef\", where 3, 4, 5 (_iA2_, _iA4_, _iF4_) shows the intersection point with the cutting plane between the source and destination. The source is denoted by \"_S_\" and destination is denoted by \"_D_\". Figure 10(e) mentions when noise propagates from source to destination through the sides of the building, then the combined route has shown. Where the blue path is the right-side route and the black one is the left-side route. (Values in x and _y_-axis are in meter).