The so-called naked eye 3D, is to let the two-dimensional plane of the picture display “real” three-dimensional effect, such as we see from the Internet a lot of street 3D special effects painting, its fake three-dimensional effect is shocking (Figure 1). Such a complex 3D effect, I and other ordinary people are not produced, but this article will introduce the method, so you only need to draw two straight lines to achieve the stereoscopic effect, and can also be produced as a dynamic map.
The two magical reference lines
We usually watch the principle of 3D movies is actually very simple, when wearing 3D glasses, facing the same screen, the audience’s two eyes see the picture is a subtle difference, these differences increase the depth of the two-dimensional plane, thus forming the illusion of three-dimensional in the minds of the audience (Figure 2).
But without the aid of 3D glasses, the naked eye is difficult to see the difference in the same picture, then we can add some reference in the picture, so that the picture has the illusion of distance between the front and back, simulating the 3D effect. The simplest reference is to add a few vertical or horizontal white lines to the screen (the lines should have a certain width). As you can see from the example below, the same picture after adding two white lines, the main character immediately stands out from the picture to produce the effect of separation, with a sense of three-dimensional (Figure 3).
Video splitting to add reference lines
Adding a white reference line to a still image is very simple and can be done with almost any image editing software. A better way is to split the video into frames, then operate on each frame separately, and finally combine them together.
In CFan’s previous article “Drag and Drop Video to Gif Quickly”, we introduced the method of breaking up video quickly through Ffmpeg. We can use this method to decompose the video, and then open it in Photoshop (this article takes CS5 version as an example) frame by frame and process it separately. If the material itself is in Gif format, or Photoshop itself supports MP4 and other video formats, there is no need to decompose the operation, you can directly open it in Photoshop, to the author’s use of Gif material, for example, after opening, Photoshop automatically placed each frame in a separate layer (Figure 4).
To follow up, we create a new layer for drawing reference lines. On the new layer, first set the foreground color to white, then right-click on the Rectangle tool in the toolbox and select the Line tool from the pop-up menu. Next, in the toolbar above, set the thickness of the line to 1 cm (according to personal preference), set the mode to “Fill Pixel”, and then draw two white vertical lines at equal distances.
Since we have to add reference lines to each frame, we make several copies of the reference line layer and place one on each frame (Figure 5).
Before continuing the operation, press Ctrl+S to save the image so that the previous work is not lost. To facilitate the operation, you can temporarily hide the unrelated layers (just click on the eye icon in front of the closed layer) and show only the two layers of the current operation (one frame frame and one reference line).
We don’t need to work with all frames. The camera angle in this example animation is rotating around the character, only when there is an overlap between the character and the reference line, we erase the overlapping part of the reference line and we are done. There are a few tips here, the first is to reduce the opacity of the reference line layer, so that you can see the image of the layer below, it is easier to operate when erasing, and then restore the opacity to 100% after erasing. The other is to press Ctrl+Shift+E at any time after each frame is processed to merge the visible layers, combining the reference line and the frame into one (Figure 6).
Exporting Naked 3D Dynamic Gifs
After processing, the next step is to generate dynamic Gif images, which is very simple in Photoshop, click the menu “File → Save as Web and device format” command (the shortcut is Ctrl+Alt+Shift+S) to open a dialog box, in the upper right corner of the storage format set to Gif Then set the parameters as needed (Figure 7). On the left side of the dialog box, there are tabs for “Original”, “Optimize”, “Duplex” and “Quadruplex”, where you can preview You can preview the effect of the image quality under different parameter settings, and preview the final file size.
As you can see, the Gif file will be very large if output in original quality, but a regular short Gif can be even compressed to about 100KB by choosing the optimized mode, which is perfect for online distribution.
After setting, click the “Preview” button below, it will automatically open the browser to preview the final effect of the animation. If you feel satisfied, go back to Photoshop and click the “Save” button to export the result as a Gif animation.
Tip: If you decompose the video by Ffmpeg and do the frame-by-frame operation in other image software, you can still take the method in CFan’s last article “Drag and Drop Video to Gif Fast” and use the command “gifski -o anim.gif frame*.png” to compose it into a Gif animation file. to make an animated Gif file.