VideoCAD

Example 22  Visualization of cameras' control area projections and spatial resolution inside them

Hide Navigation Pane

Example 22  Visualization of cameras' control area projections and spatial resolution inside them

Previous topic Next topic No directory for this topic Expand/collapse all hidden text  

Example 22  Visualization of cameras' control area projections and spatial resolution inside them

Previous topic Next topic Topic directory requires JavaScript JavaScript is required for expanding text JavaScript is required for the print function Mail us feedback on this topic!  

 

Read before: Shadow,   Spatial resolution , Spatial resolution box

 

Problem

 

We have a three-dimensional model of a complex environment.

We need to determine the areas controlled by cameras taking into account shadows arising from obstacles of the environment (camera control areas). Within the control areas, the spatial resolution of cameras must be visualized.

 

We should be able to estimate directly on the 2D site plan how people will look into the camera image at each point of the camera control area.

 

Order of work

 

1. Construct three-dimensional model of the environment using the tools of 3D modeling.

 

The constructions must be drawn by line types with marked Shadow box.

 

You can import the environment or its fragments in the form of one or several 3D models imported from other graphics formats using Autodesk 3ds Max or SketchUp.

 

 

If the environment contains 3D models,  shadows from which must be taken into account, you must:

enable calculation of shadows from 3D models in the Options box;
individually switch these 3D models into the editing state by double-clicking, then mark  the Shadow box on the Current construction parameter panel.

 

2. Place a camera. Activate it.

 

3. Choose Filling in the drop-down menu of the Fill projection button on the Tool bar.

 

View area projection will be filled by blend color.

 

The color of filling is determined by the line type of the camera.

 

4. Choose Discrete color in the drop-down menu of the Spatial resolution button on the Tool bar.

 

View area projection will be divided into the regions. The regions will be colored according to values of the criterion within the regions.

 

5. Open the Spatial resolution box.

 

In the Pattern criterion combo box you can see which criterion is chosen in the pattern assigned to the active camera.

 

 

In calculation of spatial resolution, the Vert.(Horiz.) number of pixel is taken into account.

 

 

In the Table of regions you can see what color corresponds to each range of the criterion value.

On the images in the Resolution column, you can see with which resolution people at the far bound of each region will be visible.

On the images in the Field of view column, you can see which part of the field of view people at the far bound of each region will cover.

 

 

Sample images are correct for the cameras with vertical resolution specified in the Vert.(Horiz.) number of pixel combo box.

 

See details: Spatial resolution box.

 

Don't close the Spatial resolution box.

 

6. Choose Within projection in the drop-down menu of the Shadow button on the Tool bar.

After a while VideoCAD calculates the control area projection, taking into account shadowing from obstacles in environment.

Click to expand
Click to expand

 

7. Keep the Spatial resolution box opened.

It is convenient to keep the Spatial resolution box opened during the analysis of spatial resolution in the Graphics window. Comparing color of regions on the layout with colors in the Table of regions in the Spatial resolution box, on the images in the Resolution and Field of view columns you can immediately see the expected resolution and  field of view size at every point of view area of each camera.

Click to expand
Click to expand

 

See also:Shadows,Main menu>View>Calculate shadows for active camera, Main Menu>View>Recalculate shadows,Line type>Shadow, Layers>Shadow, Options box>Miscellaneous>Shadow, Options box>Calculate shadows from 3D models, Current construction parameter panel>3D model>Shadows, 3D Models window>Shadows, Choosing the best place for PTZ (dome) camera, Visualization of the camera control area projections and spatial resolution within them