image-modelling,3D graphic,photo based visualizations
Technical University of Technology, Academic Science Circle - KAWA, P Halczuk, R. Kamiński, M. Kosicki, M. Mielnicki,
PHOTO RECONSTRUCTION ARCHITECTURE
Models building is used in many fields of science and technology. Construction of the model allows the omission of many redundant factors and the simplification of the reality of the situation enough to focus and explore the phenomenon of interest to us. This allows a simplified and fast way to show the dependence of phenomena, or presentations of a new concept formulated by the wizard. For this reason, the construction of models found its specific application in architecture. They are used to test and verify the strength of materials, and perhaps, above all, the visualization and presentation of the newly-created forms of investment. Although, the modeling and the model-building has entered a new track with the development of techniques involving the use of the computer, the story of development of techniques to help with the computer graphics and visualization used for architectural presentation can be dated much earlier. From the centuries man have felt the constant need for presenting the information about form and shape and to design tools that enable them to easily and quickly present and process the information. Sumerians perpetuated their records on clay tablets which date form about 1200 BC. The next stage on the way of devolopent of the presently understood technology, which enabled the visualization of architectural models, was the invetion of abacus by the Chinese people in 1200 AD, a geometric compass by Galileo in 1595, and the first calculating machines designed by Pascal and Leibniz. All this, in a long journey of discoveries and inventions contributed to the creation of 3D graphics.
Fig. 1. Sumer’s mud boards
Modeling, because that's how we call the traditional model of building threedimensional space, consists of solid construction using special software. Mostly, the entire model is built based on a set of basic blocks called primitives, which through various modeling techniques allow to achieve the desired effect and the final outlook of the modelated item. When it comes to modeling things which already exist or the ones being planned, it is necessary to have reference to objects and sections in order to obtain the optimal effect.
Fig. 2. Basic solids in modelling
The thing which reaches out is the modeling technique consisting of direct modeling from pictures. Currently on the market there is little application allowing direct modeling from pictures. Thanks to previously mentioned technique, you can model the whole object using only images, while maintaining the dimensions of the object. The only thing we need is pictures, and software. Photomodeling The possibilities of using this type of software are very broad. The ease with which one can attach an existing object model based on images, allows you to use them in architectural and urban visualization on large scale. They give you the opportunity to
confront the three-dimensional design with its architectural context, and not as it is today, with its pictures. Moreover, this way of modeling allows the transmis-tion of existing buildings to virtual space, and exploring them for indirect-pation Internet. The problem of mapping reality Perspective is the most realistic type of engineering drawing. Architects and designers use perspective in two ways: as the art of design and illustration draft drawn in rectangular projections. Called a perspective projection and perception of space saved by using geometric transformations. It describes the behavior of measuring the relationship between perception of space and perspective shots of forms. Perspective shot is all the methods for mapping, depending on such factors as the point from which we observe the object, its dimensions and their mutual pro-portions, positioning in space and the observer's viewing direction. The end result is a prospective application transition ob-scan illusion of space object, shown in the plane. This operation is opposite to that which we use in fotorekonstrukcji, but relies on the same dependency. During the transformation of the prospective relationship between the axes of the Cartesian system are not fixed, but at every point in space a very different and unique. The consequence of this phenomenon is the apparent intersection of parallel lines. Both the human eye and camera lens, transform the image provided for in simple terms, according to the same scheme. Background of world-rays reflected from the objects that surround us impinge image forms on the plane, which may be a volleyball, or filming. In the light of issues, more important than the photosensitive material acting as a background plane camera, more important is the mechanism for modifying the way light rays - the lens. Photoreproduction optical system requires a camera-it to the least disortion In particular, adverse-The preferred feature is that the distortion. This phenomenon is a disadvantage of the optical lens-adherent at different magnification image depending on its distance from the axis of the optical instrument. This type of aberration causes relating to the conversion of simple arcs, making it impossible to find the intersection points of view of the background radiation. This defect is mainly characterized by a large zoom lenses for the selection of lens focal length and wide. The value of the camera shutter is not without importance, which has a direct impact on the depth of field. It is a range of distances at which the objects observed by optical The apparatus gives the impression of sharp. Imane modeler
Image modeler offers the user 2 different modeling modes. Single and muliphoto modeling mode. Additionally, this 2 modes can use either ordinary Flat photo or 360 degrees panoramas. Single- photo mode:
Single panorama mode:
Single-photo mode Single-photo mode, calibration of this mode is to set the coordinate system by selecting the straight edge. Green lines, respectively y-axis, blue lines z-axis and red lines x axis.
The program examines the relative position of simple and determinate where in the Cartesian system image was taken. In the case of the panorama, program knows that the camera is in the middle, requires information only to determine the place where we start modeling, in addition to the panorama mode, the image can be rotated 360 degrees which allows potentially to reshape the entire interior of a one shot. Multi-photo modelling mode. Calibration of this mode is to select common points in different images, the minimum number of points common to the two images is 8. Remember to select the characteristic points with high contrast.
Both modes have advantages, single-photo will works at a rapid model of a single elevation model, while the multi-photo is better if we want to model the entire building around . When the building is modeled we have to texture it, the textures are flat paintings on the walls imposed by the model. Traditionally, we mark the edges to be cut to create a flat network, then in a graphics program we have to match the images with network.
Image modeler uses the same photos we used to model the building, to create a textures for it. Everything happens automatically, simply choose the type of solid ect. cube, sphere, cylinder and pres generate.
Usage of
models Digital models created in a way we described above can be used in programs where we don’t need high resolution 3d graphic. The example of this kind of usage is modeling urban environment for sustainability analysis like solar radiation, daylight calculations or shadows and reflections range (e.g. Autodesk Ecotect). These simulations can improve performance of existing buildings and new building designs. That gives us design with is friendlier for people and which can meet still increasing demands for natural environment protection. Next example of implementation is creating photorealistic 3D space which with the connection with advanced 3D visualization techniques can give very good illusion of space.
We think that modeling methods with we proposed are great balance between accuracy of designed model and opportunities of further appliance in designing process. In addition we can see great potential in that way of thinking in creation of 3d world. It is predictable that this branch of science will make huge development in the coming years. It will bring us to photorealistic visualizations of projects which with appropriate way of presentation can cause that some day we wake up in “matrix” world.
[1] ROSLLES RAMIREZ., Physics-Based Image Modelling of IVUS as a Geometric and
Kinematics System. Universitat Autónoma de Barcelona [2] FRACISCO LEGRENZI ., V-Ray the complete guite