![\"clip_image002[6]\"](\"https:\/\/www.keris-studio.fr\/blog\/wp-content\/clip_image0026_thumb2.jpg\" "\\"clip_image002[6]\\"")
<\/p>\nPhotogrammetry helps the archeologist to have a accurate orthophotos where it can be very hard to install a camera.\u00a0 But instead of just getting the final result, it could also be interresting to record each step not only for visualisation but also for calculation.<\/p>\n
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To say things fast, we wanted to record data between that :<\/p>\n \u2026 and that.<\/p>\n Before starting, the grid put on the ground has been used as a orthonormal. Three points were set : A(0,0,0), B(1,0,0) and C(0,1,0). Those points were then used in Photoscan to scale the model and stack all 3D geometry.<\/p>\n The following work does not need a very dense geometry, it will be easier to process with a lighter model, but it\u2019s necessary to keep a large texture for visual details.<\/p>\n In this example, I chose 10% as I knew I would have in the end a stack of 10 files with about 100 000 polygones each.<\/p>\n The texture has to be recalculate. When finished, the model can be exported in OBJ.<\/p>\n All layers, every step are gathered as shown below.<\/p>\n Step by step :<\/p>\n The following is done with Autodesk 3DsMax<\/strong>, but all kind of 3D software : Blender, Maya, Cinema 4D or Modo could be used the same way.<\/p>\n After importing, scale has to be checked.<\/p>\n All objects are grouped. When done, apply\u00a0 \u00ab Modifiers \/ Slice<\/b> \u00bb and click on the\u00a0 (+) sign to make the \u00ab Slice Plane<\/b> \u00bb Gizmo active. Rotate the Gizmo 90\u00b0 and then clich on \u00ab Remove Top<\/b> \u00bb or \u00abRemove bottom<\/b> \u00bb to see the slice..<\/p>\n Then apply \u00ab Edit Poly \u00bb Add an \u00ab Edit Poly<\/b> \u00bb When selected, change \u00ab Material ID<\/b> \u00bb set it to\u00a0 2 for exemple. Set new materials as shown. Each slice gets a \u00ab Multi-sub Object \u00bb texture with in Slot 1, the original texture and in slot 2 the colour given the cut section .<\/p>\n Final result in perspective.<\/p>\n Final result as orthophoto.<\/p>\n Cut sections can also be colorized depending to the height.<\/p>\n Orthoview.<\/p>\n Working with the void, it will be possible to determine some quantities.<\/p>\n This is easy to do using the last step.<\/p>\n The \u201chole\u201d needs to be isolated<\/p>\n The top section is capped The volume is calculated : 6,63 m3<\/sup>.<\/b><\/p>\n All steps will be added starting from the very first one.<\/p>\n Step 0 will be the \u201clid\u201d of the following step.<\/p>\n The \u201clid\u201d is set over the geometry. Beware : faces underneath have to be flipped in order to fit with the top.<\/p>\n Step 1 and 2 are glued.<\/p>\n Next step :<\/p>\n The position of the root is clearly visible.<\/p>\n Next step :<\/p>\n Next one with a hard layer.<\/p>\n Last one.<\/p>\n![\"clip_image002[4]\"](\"https:\/\/www.keris-studio.fr\/blog\/wp-content\/clip_image002410.jpg\" "\\"clip_image002[4]\\"")
<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\nSimplification and export from Photoscan<\/h4>\n
<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/a><\/a><\/a><\/a><\/a><\/a><\/a><\/a><\/a><\/p>\nSuperposition and visualisation of the excavation.<\/h4>\n
<\/a><\/p>\n<\/a><\/p>\n<\/a> and a \u00ab Shell<\/b> \u00bb.<\/p>\n<\/a><\/p>\n<\/a> to modify the colour of slices.\u00a0 Select by angle.<\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\nQuantities<\/h4>\n
Volumes.<\/h5>\n
<\/a><\/p>\n<\/a><\/p>\n<\/p>\n<\/a><\/p>\nCalculation for each step.<\/h5>\n
<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n