Mount 3D Model in Image

Task area Shadow

You can use this tool to insert 3D models in bitmap images, for example, a planned building in a photograph of the planned site. In addition, you can identify the eye point, target point and the vanishing points in a scanned photograph.
Optical distortion of photographic lenses and the section scanned of the photograph combined with the resolution of the screen restrict the accuracy of this operation. This means that corrections or even a number of attempts may be necessary until you are satisfied with the result.

Before you insert a complex architectural structure, use a simple outline model of the same shape, consisting of 3D objects. Once it fits, you can save it before you replace it with the complex model.

Note: This tool is particularly useful for perspective views in which vanishing points are clearly visible. For example, think of corner buildings. Aerial views, however, are not so suitable.

To mount a 3D model in an image

1. Select the drawing files with the 3D model.
2. The 3D model has to be displayed in central perspective (= vanishing point projection mode).
   Click 3D View (How) on the viewport toolbar and select Perspective view.
   

   Activate 3D View in one of the following ways

   • Menu bar: View Views

   • Toolbar: Viewport toolbar
3. The 3D View palette opens. Set a perspective view which roughly corresponds with the one you require for inserting the photo.

   Tip: In the 3D View palette, set the Focal length so that it matches the value used for the photo. For digital photos, you can find this value in the Properties of the file - Details - Focal length of 35mm.

   Tip: You can also set the perspective view in a viewport with the Animation view type.
   All you need to do is click Match parameters in the 3D View palette. Then click within the viewport with the Animation view type. This is only possible if Navigation Mode is not active

   Tip: You can make things easier by creating a hidden line image of the model: Select the Hidden line image view type at the bottom of the viewport.

4. Click Mount 3D Model in Image (How).
   

   Activate Mount 3D Model in Image in one of the following ways

   • Actionbar:Role Draft Task Visualization Task area Shadow

   • Menu bar: Create Presentation Animation

   • Palette: Tools Create area in the following module(s):

   Animation

5. Select the format and name of the bitmap image with the scanned photograph.

   The program opens a window with the 3D model. The window's height:width ratio matches the photograph's height:width ratio.

   If the bitmap image of the photograph is larger than the display resolution, it is fitted into the workspace.

6. The following steps involve defining the exact perspective view of the 3D model to be inserted. Specify a reference line on the 3D model and two pairs of vanishing lines (see below).

   Note: Enter the angle included by the two pairs of vanishing lines in plan view.

   

   (A) 3D model
   (B) Photo
   (C) New building
   (D) This angle must be known in plan view (see step 11).
   (E) First vanishing point (not visible)
   (F) Second vanishing point (not visible)
   Note: The two vanishing points (E) and (F) must be at the same height.
   (1)+(2) Identify the reference line on the 3D model. The photograph is hidden (see step 8).
   (3)+(4) Click a corresponding reference line in the image. The photograph will reappear (see step 9).
   (5)+(6) Specify a second line leading to the same vanishing point (see step 9).
   (7)-(10) Specify two lines leading to the second vanishing point (see step 10).
   (11) Place the target point. You can place it as often as necessary - until you have found the correct one and while the tool is still active (see steps 12/13).

   Tip: Draw the required reference lines in a copy of the bitmap image and use this copy to fit in the model. To render the model subsequently, click Surroundings (How) and select the image without vanishing lines.

   

   Activate Surroundings in one of the following ways

   • Actionbar:Role Draft Task Visualization Task area Surfaces, Light

   • Menu bar: Change Presentation Animation

   • Palette: Tools Change area in the following module(s):

   Animation

   • Shortcut menu: Navigation Mode selected - Right mouse button
7. Click a reference line in the 3D model, see illustration (1) + (2).

   The photograph will reappear after you have done this.

8. Now click a line in the photograph which corresponds to the reference line you just specified in the model, see illustration (3) + (4).
9. In the photograph, click a second line leading to the same vanishing point, see illustration (5) + (6).
10. To define the second vanishing point, specify two lines again which lead to it in the photograph, see illustration (7) - (10).

    Note: When the message The horizon is inclined at 1.5 degrees. An inclined horizon cannot be displayed. appears, do the following:

    • Repeat steps 8 to 10. Use different reference lines.
    • Check whether the horizon on the photograph is actually inclined or whether the scanned photograph is inclined.
11. Enter the angle in plan view included by the two pairs of vanishing lines, e.g. the angle between boundary lines, two buildings or cornering walls, see illustration (D).
12. Click the target point, see illustration (11).
    On photographs, the target point is normally the center of the image. However, it can shift from the center through scanning, magnification, section etc.
13. You can correct the target point as often as you like.

    The 3D model is redrawn on top of the photograph.

14. Once you have found the correct target point, press ESC.

    Now you can save the correct target point and use it for the calculation of the complex model.

15. Click Yes to render the view using the bitmap image as a backdrop.

    Note: Using Surroundings (How), you can activate or deactivate a bitmap image for the background at any time.

Note: The perspective view is displayed as a wireframe model. You can use the Render tool to render the perspective view with the photo (bitmap image) in the background.

Note: You do not need a Virtual ground plane for rendering an image with a bitmap image in the background. Open the Surroundings tool (How) and switch the ground plane off.