These are just some simple instructions for rendering publication-style images of crystal structures. Hopefully someone else will find them to be useful.
Mac (via Homebrew): brew install povray
Windows: download and run the installer from here
Download the version for your computer here
The most important part is getting the view angle you want, but ovito also makes it really easy to make a supercell, change atom colors, remove cell boundaries, add bonds, etc.
file > Export File > select POV-Ray scene
def shinify(
input_filename, output_filename, specular=0.8,
reflection=0.8, diffuse=0.8, light_intensity=1,
light_location=(None, None, None)
):
"""
Adds finish properties to .pov output files generated from Ovito.
args:
input_filename (str): existing .pov file created by Ovito
output_filename (str): desired filename for "shiny" .pov file
specular, reflection, diffuse: finish parameters from POV-Ray, applied to spheres (atoms) and cylinders (bonds)
see https://www.povray.org/documentation/view/3.6.1/79/ for more details/options.
light_intensity (float): multiplier for light intensity
light_location (tuple): x, y, and z coordinates of light fixture in the scene. You might have to use trial
and error to find the best location if Ovito's default isn't what you want.
"""
lines = open(input_filename).readlines()
with open(output_filename, "w") as f:
i = 0
light_fixed = False
while i < len(lines):
line = lines[i]
# Add your own lighting
# you can also mess with the light color and its intensity
if line.split()[0] == "light_source" and light_location[0] is not None:
f.write(
"light_source {\n"
+ f" <{light_location[0]}, {light_location[1]}, {light_location[2]}>\n"
+ " color <{light_intensity}, {light_intensity}, {light_intensity}>\n"
+ "}\n"
)
i += 6
# Add shiny finish to spherical atoms
if line[0:14] == "#macro SPRTCLE":
f.write(
"#macro SPRTCLE(pos, particleRadius, particleColor, spc, ref, dif) // Macro for spherical particles\n"
+ "sphere { pos, particleRadius\n"
+ " texture { pigment { color particleColor } finish { specular spc reflection ref diffuse dif } }\n"
+ "}\n#end\n"
)
i += 4
elif line.split("(")[0] == "SPRTCLE":
f.write(line.replace(")", f", {specular}, {reflection}, {diffuse})"))
# Add shiny finish to cylindrical bonds
elif line[0:10] == "#macro CYL":
f.write(
"#macro CYL(base, dir, cylRadius, cylColor, spc, ref, dif) // Macro for cylinders\n"
+ "cylinder { base, base + dir, cylRadius\n"
+ " texture { pigment { color cylColor } finish { specular spc reflection ref diffuse dif } }\n"
+ "}\n#end\n"
)
i += 4
elif line.split("(")[0] == "CYL":
f.write(line.replace(")", f", {specular}, {reflection}, {diffuse})"))
else:
f.write(line)
i += 1
shinify("ovito_file.pov", "ovito_file_shiny.pov")povray +H800 +W800 +Iovito_file_shiny.pov +Oovito_file_shiny.png +UA
+H & +W: image height and width in px. I usually go well into the 1000's for a final publication image, but ~800 is fast for testing.
+I & +O: povray filename and image filename, respectively
+UA: allow for transparency (alpha), I like it for creating clear .png files
The y-axis in POV-Ray is generally "up", while z is generally "depth". For example, in the image below I also added a reflective plane under the atoms. I just added a line at the end of the shinify function:
f.write("plane {<0, 1, 0>, 9 texture {pigment { color rgb <1, 1, 1> } finish { specular 0 reflection 0.2 diffuse 0.4}}}")You can see that the plane is normal to the y-axis.
I also use a lot of trial and error for the lighting location and intensity, and for adding other objects (blocks, discs, etc.) to the scene.
You will have to consult the POV-Ray documentation for all the possible things you can add and change- it goes WAY beyond what I've achieved in this small example. There is also quite a large community of POV-Ray expert users creating example scripts that you should make liberal use of. For example, I just buried the above ovito atoms scene in an underwater scene I found here to get the image below:
