Photomontage and cast only shadows.

[stamos]

<p> For those who like creative photomontage the technique of casting only shadows may be interesting and may help you.<br>

To integrate a photo of an object in a complicated 3D environment you need accurate shaddows.<br>

You may create a 3D object similar to the object in the photo (that you want to integrate) and make it cast only shadows (it will remain invisible with visible only it's shadows).<br>

Then in the position of the invisible 3D object you paste the (cut and copied) photo.</p><div></div>

[stamos]

<p>Here is the 3D environment:</p><div></div>

[stamos]

<p>Here is the photo of the object:</p><div></div>

[stamos]

<p>Photo cut:</p><div></div>

[stamos]

<p>Now I create a similar 3D object:</p><div></div>

[stamos]

<p>And I make the 3D object cast only shadows (it is invisible but it is casting normal shadows)</p><div></div>

[stamos]

<p>It is important:<br>

The points of view in the photo and in the 3D to be (nearly) the same.<br>

The light source in the photo and the 3D to be in the same point (nearly) and to have the same (nearly) parameters.<br>

In this example things are rather simple but there cases with many light sources, with semi-transparent objects (half-full bottles of liquids) and with many frames (animated montages).<br>

I use this technique in my work: "Andromeda dream" and others.<br>

I hope you find this interesting.</p>

[py-photography]

<p>Very interesting and cool as well. Thanks for sharing.</p>

[John Seaman]

<p>Stamoulis, thanks for sharing this, but I'm going to show my ignorance by asking, what software do you need for this? I'm reasonably familiar with Photoshop but "cast only shadows" doesn't seem to be an option.</p>

[stamos]

<p>Thank you for nice words.<br>

The "cast only shadows" is an option for a 3D object in 3D environment not in 2D image processing software. So you need a 3D software to create and render 3D objects.<br>

First create the 3D (with a 3D software), then render the 3D (with a 3D software) in a file format that preserves transparency and then process this file (with a 2D image processing software).<br>

A nice 3D software you can find here: <a href="http://www.blender.org/">http://www.blender.org/</a> <br>

I will try to make some basic tutorials for Blender 3D here in Photo.net.</p>

[stamos]

<p>In Blender 3D software, in Buttons Window, in Shading, under Links and Pipeline, under Render Pipeline there is the option "Only Cast". Here the "Only Cast" is OFF.</p><div></div>

[stamos]

<p>Here the "Only Cast" is ON.</p><div></div>

[stamos]

<p>Here is a screen capture of Blender 3D software with the 3D View Window (up left), the Outliner Window (up right) and the Buttons Window (down).</p><div></div>

[stamos]

<p>You can see the real power of this technique in complicated and dynamic environments. See the following images that could be frames of a small video.<br>

Image #2</p><div></div>

[stamos]

<p>Image #3</p><div></div>

[stamos]

<p>Image #4</p><div></div>

[stamos]

<p>Image #5</p><div></div>

[stamos]

<p>Image #6</p><div></div>

[stamos]

<p>Image #7</p><div></div>

[stamos]

<p>Not only the background can change dynamically but also the foreground (independently).</p>

[stamos]

<p>Here the real object captured with the real camera changed position in the real space.</p>

[stamos]

<p>Real object, captured with real camera in real space.</p>

[stamos]

<p>Real object.</p><div></div>

[stamos]

<p>Photo Cut.</p><div></div>

[stamos]

<p>Here the 3D object (in 3D software) captured with the camera (in 3D software) changed position in the xyz space (in 3D software).</p><div></div>