Focal Stacks

OBJ Files

Requirements for OBJ files for CalVR to display:

• Material library file needs to be specified with extension, e.g.: mtllib coral-mtl.mtl.
• To use a texture image (image map) use the command usemtl, not usemap. Example: usemtl coral-material. This is for material file coral-mtl.mtl, which has the following content:

  newmtl coral-material
  map_Kd coral-map.jpg

• The image referenced by the material file in this example is coral-map.jpg.
• If the image is upside down, flip it with the following ImageMagick command:

  convert sourceimage.jpg -flip destimage.jpg

• Here's a script that converts Helicon Focus's OBJ files to CalVR's OBJ format:

#!/bin/bash
#
# Syntax:  <scriptname> <obj_file_name.obj>
# Example: conv2calvr.sh FS_010.obj
#
chmod 660 *
sed s/usemap/usemtl/ $1 -i
sed s/map.jpg/coral-material/ $1 -i
sed '/map_Kd/ i\newmtl coral-material' $1.mtl -i
convert $1.jpg -flip $1.jpg

• To run the script on all OBJ files in a time series:
  • Put the above script (conv2calvr.sh) in the directory just above the directories for the time series.
  • Call the following command in a bash shell:

find . -type d -exec sh -c 'cd {} && echo `../conv2calvr.sh *.obj`' ';'