The camera match for these photosims was made easier by the documenting of the view location while in the field. The shot was taken adjacent to the existing parking lot near a curve that was visible in the plan drawings and a high resolution aerial. A yellow line represented the camera location and approximate view direction.
A Geopak design model was developed for the two alternatives and was used to produce 3D models of each of the designs, including cut and fill slopes, and proposed retaining walls. This model was exported as a DXF file and imported into 3D Studio Max. (The preferred method in V8 would be to 'Save As' a DWG file which can then be opened directly in 3DS Max. Section 4.3 discusses some issues with exporting Microstation data to 3D rendering applications.
The camera matches to the background photos for this project were done in 3DS Max, which allow the user to interactively move the camera and camera target while displaying the 3D model over the background. The process is the same as the matching process described for Microstation in section 4.2. The surfaces in 3DS Max can be rendered in the viewport as wireframe or shaded, just as in Microstation.
The Microstation model included a geo-referenced high-resolution aerial that covered most of the project. Having this aerial which exactly matched to the plan data helped in two ways. It was easier to confirm the camera location visually, and it allowed the identification of features that were visible in both the background photo and the aerial. These features (in this case some trees and rocks) could then be interpreted from the aerial in plan, and modeled roughly as lines or simple objects to help with the camera match.
Aerial photo - the open area on the road is visible in the background photo.
Aerial attached to Microstation model file.
This model was brought into into Microstation V8 and then saved directly as a DWG file which was then be imported into 3DS Max. The existing road, seen as a denser horizontal surface was visually lined up with the road in the photo, and the ridge line had to be visually 'interpolated' as the ground line at the base of the trees. There were a couple of small lines in the model that were drawn over the aerial showing locations of some features- trees and rocks, that were lined up with elements in the photo.
The surfaces imported from Microstation showed the extents of the cut slopes and the walls for each alternative. Using a rock wall texture, and cut slope texture pulled from the background photo, features of the two alternatives were painted to represent the proposed new features. The stone texture was originally created using a light stone texture map, but in order to match the surrounding features- especially the cut, the stone layer was tweaked in Photoshop using level controls to portray a darker material. A highlight was added along the top to mimic the strong light from above and to the right. Where possible, the textures used should match the lighting in the photo in both quality and direction.
Stone texture for wall - look for repeating image..
Layers are used to separate the different elements in the scene for easy changes to individual features. In this layer table, there are background changes- trees being removed or changes to lighting based on the project; the new features- cut slope, wall, and rail; and then details pulled from the background layer that would be in front of the new features.
|
