1 Efficient rendering of terrain elevation model
3 start with some top level cells
9 views from google earth
11 image data + info viewing / illumination
16 [ ] seems - not important
18 [ ] selection of channels to display
19 [ ] more sensible sampling of elevation data
20 [ ] edges of box should interpolate
21 [ ] inner vertices should be sensible
24 [X] gui to toggle {flat, unprocessed, corrected -> refined}
26 [X] focus extended altitude
27 [X] mouse click -> lon lat transformation
28 [ ] terrain grab while dragging
29 [X] selection of region
30 [ ] region image preview (full resolution)
32 [ ] in region, detect shadow areas
33 [ ] border and highlight in both views
40 16801 x 14921 - 250MB x1
43 downsample entire image to a reasonable size
44 1/8 x 1/8 = 1/64th size = ~10MB
45 or use the thumbnail in each image
46 when a portion of the image is desired in higher detail
47 reload portion of the image at full resolution
48 1/8 x 1/8 = 1/64th size of image
49 when a portion of the image is no longer being used
61 determine if we need to subdivide quality in this cell
62 if we're close, then we do
63 find distance from each corner
64 use distance[i] < max(dist(corner[i], corner[j]))*factor
65 if we should subdivide
66 renderCell on each of the 4 subdivisions
67 determine the quality at this level
68 find distance to center
69 apply magic function to find detail level
70 render the cell in this detail level