Owlet can render scenes in batch mode without showing any user inteface. You can use this for batch rendering, hot folders, rendering on demand on websites or for any other purposes.
Note that each dedicated rendering node needs its own Owlet license
The simplest command line rendering example is:
Owlet.exe --render scene.owletScene
On Mac OS you need to type:
Owlet.app/Contents/MacOS/Owlet --render scene.owletScene
We’ll keep using Windows .exe synthax below, on Mac OS you simply need to change Owlet.exe with the path above. All the rest is the same.
This command tells Owlet to read scene.owletScene file, render it with all the settings by default and save image to scene.owletScene.png. You can provide some extra parameters to adjust the rendering process to your needs.
When Owlet renders a scene in batch mode, it first of all sets up its rendering engine to use default settings: 2000 iterations, 512x512 pixels resolution, caustics off. Then Owlet reads scene file for saved rendering preferences. You set them in rendering settings window right before you click Start button there. These settings override defaults. Finally, Owlet checks if any command line parameters are specified. They then override the settings, as well. When all that is done, Owlet starts rendering.
So if you make a new scene and render it once with 800x600 resolution and caustics enabled, then save the scene and render it using the line above, you’ll get a 800x600 image with caustics, rendered with the same number of iterations (or for the same time), as you specified in rendering settings before saving. Owlet will basically repeat your last rendering.
However, if you do this:
Owlet.exe --render --width=1024 --height=768 --output=res.jpg --seconds=10 scene.owletScene
You’ll override resolution with 1024x768, tell Owlet to save image to res.jpg in JPEG format and ask it to render it for 10 seconds. This way you override your last saved settings and that is what you’ll most likely want to do in practice.
The other options can be specified that way:
Owlet.exe --render --width=600 --height=400 --passes=20 --output=image.png --algorithm=UPBP --photon-scale=2 --max-intensity=20 scene.owletScene
The line above enables caustics, sets photon scale to 200% and max intensity to 20.
The –tile option is epxlained on its own page.