（圖像三維建模）Agisoft PhotoScan Professional 1.0.3

它是如何工作的
在一般的照片處理由PhotoScan的最終目的是建立紋理的三維模型。照片處理和三維模型構建的過程內含三個主要階段。

1 .第一階段是照片對齊。在這個階段PhotoScan搜尋照片上的共同點，它們相符合，以及它找到相機的每個畫面的位置和完善的攝影機標定參數。其結果是稀疏的點雲和設定攝影機位置的形成。

點雲代表的照片比對的結果，並不能直接用於進一步的三維模型構建過程中（在基於點雲的重建方法除外） 。但是它可以通過外部工具可以匯出為進一步使用。例如對點雲模型可以在三維編輯作為參考使用。反之將需要進一步的三維模型構建由PhotoScan設定的相機位置。

2 .下一階段正在建設的幾何形狀。根據估計的攝影機位置和圖片本身PhotoScan構建3D多邊形網格，即物體表面。在PhotoScan四種算法可用的方法可應用於三維網格生成：任意 – 平滑，任意 – 夏普，高度場 – 平滑和高度場 – 夏普方法。此外，還有一個僅僅基於稀疏點雲點雲為基礎的方法進行快速幾何生成。構建網格之後，可能有必要對其進行編輯。一些修正，如網狀抽取，去除分離元件，收盤孔的篩網等可以通過PhotoScan進行。對於更複雜的編輯，你必須聘請外部的3D編輯器工具。 PhotoScan容許匯出網格，由另一個軟體編輯並匯入了回去。

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【文章標題】: （圖像三維建模）Agisoft PhotoScan Professional 1.0.3
【文章作者】: 錄影.剪接.編輯教學密訓基地
【作者信箱】: ster168ster@gmail.com
【作者首頁】: http://por.tw/photo-video/
【錄影.剪接.編輯教學課程】: http://por.tw/photo-video/video_Course/index.php
【基地主機】: http://goto1688.com/photo-video/
【版權聲明】: （原創）錄影.剪接.編輯教學密訓基地，轉載必須保留完整標頭。刪除者依法追究！
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Agisoft PhotoScan Professional 1.0.3

Agisoft PhotoScan is an advanced image-based 3D modeling solution aimed for creating the professional quality 3D content from still images. Based on the latest multi-view 3D reconstruction technology, it operates with arbitrary images and is efficient in both controlled and uncontrolled conditions. Photos can be taken from any positions, providing that an object to be reconstructed is visible on at least two photos. Both image alignment and 3D model reconstruction are fully automated.

How it works
In general the final goal of photographs processing by PhotoScan is to build the textured 3D model. The procedure of photographs processing and 3D model construction comprises three main stages.

1. First stage is the photographs alignment. At this stage PhotoScan searches for common points on photographs and matches them, as well as it finds positions of the camera for each picture and refines the camera calibration parameters. As a result the sparse point cloud and the set of camera positions are formed.

The point cloud represents the results of photos alignment and will not be directly used in the further 3D model construction procedure (except the point cloud based reconstruction method). However it can be exported for further usage by external tools. For instance the point cloud model can be used in the 3D editor as a reference. On the contrary the set of camera positions will be required for further 3D model construction by PhotoScan.

2. Next stage is building the geometry. Based on the estimated camera positions and pictures themselves PhotoScan builds the 3D polygon mesh, representing the object surface. The four algorithmic methods available in PhotoScan can be applied for 3D mesh generation: Arbitrary – Smooth, Arbitrary – Sharp, Height field – Smooth and Height field – Sharp methods. Additionally there is a Point Cloud based method for fast geometry generation based on the sparse point cloud alone. After building the mesh it may be necessary to edit it. Some corrections, such as mesh decimation, removal of detached components, closing of holes in the mesh and so on can be performed by PhotoScan. For more complex editing you have to engage external 3D editor tools. PhotoScan allows to export the mesh, edit it by another software and import it back.

3. After the geometry (i.e. the mesh) is generated, it may be textured and/or used for orthophoto generation. Several texturing modes are available in PhotoScan, they are described in the corresponding sections of this manual.