Photobump User Manual

Basic Usage

1. Start the application by launching Photobump20.exe in the Crytek\CryENGINE\Tools\Photobump directory.
2. On the File menu select Open and browse to the 'Pictures->Tutorial_Example' folder.
3. There are only 2 files in the folder, a pair of low resolution rock photos: DSCN0013.JPG and DSCN0014.JPG
   
4. Click on the first file of the sequence (DSCN0013.JPG)
5. The dialog reconstruction option will pop up
   
6. Click Ok.
7. The process will start. A progress bar will show you the completion status.
8. After a couple of minutes the interactive OpenGL preview will show the reconstructed model:
   
9. In the folder a number of files will be created. These files are a cache of the computed model, so the next time you run Photobump it will find the files and it will skip the whole reconstruction process. You can now just tweak normal map detail and scale, if you need to. To do so, run the same steps from 1 to 6, and in the Reconstruction Dialog (Point 5).
   Normal Map Scale lets you tweak the 'strength' of the final normal map. The higher the value, the 'stronger' the resulting normal map will be.
   Details Scale lets you add small cracks and bumps on top of the reconstructed surface, taken directly from the photo. The higher the value, the stronger the details will appear in the final normal map.
   Show initial matches only will only calibrate the cameras, show their reconstructed position and the initial 3d seed points, without generating the normal map. Useful when you need to debug problems with the pictures (see Figure 9 in the Photobump Technical Document).
10. The normal map will be generated in the same folder with name DSCN0013.JPG-NormalMap.tga.
    

User Keys

Keys 1-2: Switches between the 2 recovered cameras positions.
Key L: Shows the model with basic GL lighting, without texture.
Key S: Shows the model in texture mode.
Key W: Wireframe mode.
Mouse movement with right mouse pressed: changes view direction
Mouse movement with left mouse pressed: navigates in the current view direction

Taking the Pictures

First of all you need to take two photos of the subject of interest. To see some additional examples, look at the Photobump page.

• The first photo of the sequence you take will be used by the tool as 'reference photo' for geometry and normal map generation.
• Try to take the first photo in front of the object.
• Step to the right and take the second photo, while still trying to point at the object's center. You need to move enough to give the tool information about the object's shape ' there isn't a precise rule because it varies from subject to subject. The closer to the object, the less you should move. For a better understanding, look at some of the photo samples. Some of the best results have been obtained when moving a lateral human step for about every 2 meters of distance from the object.

View from the top:

• Do not change focal length from one picture to the other.
• Do not take pictures when having the sun in front of you.
• Avoid having moving elements (cars, people, your own body etc.) in the picture.
• Do not take picture when you are drunk: try not to rotate the pictures too much around the camera axis centre (drawn in light blue in the picture above), take clean pictures of the subject.

View from the camera position looking at the object

THIS IS CORRECT:

THIS IS NOT CORRECT:

• Put each pair of pictures into a separate folder with progressive names (like DSC001.jpg, DSC002.jpg) etc.

• Both pictures must have the same resolution. The bigger the picture, the longer it takes to compute the normal map.
• If you need to resize the pictures, use the Bilinear Filter in Photoshop.

Additional Bonuses

Batch tool
A Batch tool is provided to process several files at once, in standalone mode. Put each pair of pictures into a folder as explained in Point 8 in the 'Taking the Pictures' section. All folders should go into a subfolder called 'BatchProcess'. The Photobump executable should have the name Photobump20.exe in order for the batch tool to find it. So don't rename the executable.

For example:

The batch tool will then scan the 'Pictures' subfolders recursively and invoke Photobump.exe with a command line.

Obj Exporter
You can export an .OBJ file of the model. Go to File->ExportObj and select a folder and a file name. Be careful as it would easy generate a file in the order of hundreds of megabytes.

Align Normal map
It will align an existing normal map to (x=0,y=0,z=1) (z axis pointing up). Go to File->ExportObj and select a normal map file. Note that Photobump aligns normal maps by default, so you don't need to do that on normal maps generated by Photobump.

Import Bojou calibration data
You can import cameras calibrated with Bojou (a commercial camera calibration software). In Bojou you must export a .txt file. Go to File->Open and select the .txt file.

Optical flow
An optical flow visualization of movies. Go to File->Open and select an .AVI file. A window will pop up showing the optical flow. Press spacebar to move through each frame of the sequence.