Camera Map Modifier

This modifier applies planar mapping coordinates to an object projected from the viewpoint of a specified camera. The main purpose is to map an object in such a way that it perfectly matches the backgroundand yet fix the mapping to the object so that if you move or otherwise distort the camouflaged object, it becomes visible against the unchanging background map.

In order to make the illusion work, you must assign the same map to the background as you assign to the object. In addition, because the accuracy of mapped objects is partly dependent on the complexity of the mesh, the effect works best when applied to an object with a relatively high density of triangular faces. The necessary density also depends on the distance of the object from the camera. A simple box might look fine when it occupies only a small portion of the background, but up close the mapping will look distorted without adequate tessellation. A bit of experimentation is require to get an ideal mapping and still minimize the complexity of the geometry. (In general, for a box object that’s filling a quarter of the screen, a tessellation of 4x4x4 works fine.)

Note: Keep the following in mind when using the Camera Map modifier:Apply the modifier to a single object at a time. If it’s applied to a selection set, only the first item in the selection will be mapped properly.

To make the coordinates “stick” to the surface of the object, apply the modifier in the Stack before and animated modifiers that distort the object. Also, make sure that any animated modifiers begin their animation after frame 0, otherwise the mapped object will not match the background at frame 0.

ART DIRECTIVE( Object against a background Before and After)

Reference

Camera Mapping Parameters

Pick Camera: The Camera Map modifier contains a single button, labeled Pick Camera. To apply the UVW coordinates, click the Pick Camera button, and then select the camera through which you’re going to view the scene.

How To

The following steps show how to apply the Camera Map modifier, and how to set up your scene.

To apply the Camera Map modifier, to this:

1. Create a scene with a camera and one or more objects. Make sure the object you want to map is visible in the camera viewport.
2. Select the object, and apply the Camera Map modifier.
3. If you have animation in the scene, move to the frame at which you want the object map to match the background. For example, if the camera is animated, the mapping will match only at this frame.
4. Click the Pick Camera button, and the select the camera used for the rendered view.

Next, assign a background image to the camera viewport:

This is not really necessary for successful rendering, but if you want to see the effect in a viewport, do these steps.

1. Activate the camera viewport and turn off the grid.
2. From the Views menu, choose Background Image.
3. Click the Files button, and choose the same bitmap that you plan to apply as a background for the rendered scene, and as a diffuse map on the object.
4. In the Aspect Ratio area, choose Match Rendering Output.
5. Check Display Background, and click OK.

The map is displayed in the viewport.

Now, assign a mapped material to the object:

1. In the Materials Editor, create a standard material to whose Diffuse channel you’ve assigned the same bitmap as you assigned the background.
2. At the Diffuse Map level of the material, turn on the Show Map in Viewport button.
3. Select the object, and click Assign Material to Selection.

The map on the object in the viewport matches the viewport background, but the shading makes the object visible. To make the object truly invisible, add the following steps:

4. At the top level of the object’s material, set Shininess and Shininess Strength to 0, and set Self Illumination to 100.

The object is now camouflaged against the background.

Finally, assign the background to the rendered background:

1. In the Material Editor, select an unused sample slot, and open the Materials/Maps Browser.
2. Choose Browse From Mtl Editor.
3. Turn off Root Only, make sure the Show Maps is checked, find the map in the list window, and drag it over the unused sample slot.
4. Choose Instance in the alert, and click OK.

The map is now in the sample slot.

5. In the Coordinates rollout of the Materials Editor, choose Environment, and then set the drop-down list to Screen.
6. From the Rendering menu, choose Environment.
7. Drag the sample slot containing the new map over the Background button in the Environment dialog.
8. Choose Instance in the alert, and click OK.
9. Render the camera viewport.

The mapped object is camouflaged against the background in the rendered scene.