Adding Texture to the 3D Object
Once the basic lighting and surface properties were in place, I wanted to create the sense of texture, by using a bump map. The bump map's effect is controlled with the Bump Strength setting shown in Figure 3.
For this image, I wanted to create a sort of mottled, almost "liquid" look for the surface of the orb. To create the bump map, I opened an empty white document with roughly the same dimensions as the original image and chose Filter > Render > Clouds to produce a smoke-like texture. The smoky texture is based on the foreground and background colors displayed on the toolbar, so I used simple black-and-white. We'll come back to this bump map shortly.
Figure 3 The "Filter by: Materials" view in the 3D panel is where you define the surface properties of your object. Here, settings were optimized for a mirror-like effect.
I also needed to create a texture that would generate the "reflection" on the surface of the orb. I made a copy of the original background image, cropping it so that less ground was visible, and showing only some of the clouds. This gave the appearance that less ground and more sky was seen from the photographer's vantage point when looking at the orb's reflection. Conversely, if the vantage point were directly beneath the orb, all we would see is ground being reflected back at us. For that result, I could leave the ground regions on the copied image intact, and crop away the clouds, perhaps experimenting a bit to find just the right look.
Experimentation is required when creating reflective textures, but it's fairly easy to get a good result after a couple of tries. The objective is to find a result that looks real enough that people will just enjoy the image, without noticing things that might cause them to analyze it. That is, unless your core audience is composed of physics professorsin that case, a scientific-looking result becomes a bit more critical!
For some images, the Specular option in the Materials view would also have a pronounced effect, but here it was barely noticeable, so I chose a greenish-white to mimic the color castoff from the green plant life. I unchecked the Two-sided option, because only the outside of this material needs to be lit (like a real mirror).
The final step for my floating orb was to apply the two texture files I created directly to the orb. To apply the bump map image, I clicked the button next to the Bump Strength item in the Materials view, and chose the Render Clouds file described earlier. This provided the desired mottled look. Finally, I clicked the button next to the Reflectivity option and selected the cropped background scene image. Once these two textures were applied, the 3D object immediately took on a much different look.
The glass-like reflection was created by using a moderate value for the Glossiness and Shininess settings, and 100% Opacity and Reflectivity. The Bump Strength option defines the smoothness of the surface. The higher the setting, the more it "maps" the values from the bump texture to create variations on the surface. I chose a relatively "smooth" setting to give the orb a watery appearance. Figure 4 shows the finished image.
Figure 4 The finished 2D/3D image is completed using only Photoshop CS4 Extended and a single photograph.