C4D workflow
A video showing the setup steps described on this page. This scene is provided through the link at the bottom of the page.
1. Create a lentil camera
From the arnold menu, add a lentil_camera camera.
2. Set up parameters in the camera attributes
Set param: units to the same value as the export scale in the global render settings.
Set the bidirectional sample multiplier param: bidir_sample_mult. The bokeh samples are decoupled from the AA sample count. A good interactive baseline is around 1-10, although you might want to increase this when dealing with very small highlights, or decrease it when dealing with larger high luminance areas. Lentil will automatically modulate the sample count based on the screenspace area footprint of the bokeh.
3. Add the Lentil Operator
In the global render settings, navigate down to the Advanced section. There you will be able to create a new lentil_operator. No additional settings have to be adjusted here.
This operator will inject the correct lentil filter to all AOVs.
4. Add the Lentil Imager
In the global render settings, click on "Effect...". From there, add an Arnold Imager & switch it to lentil_imager.
lentil_imager needs to be the first imager in the imager stack. It cannot accept inputs from other imagers, unlike the default arnold imagers.
5. (optional) Double check the samples that will trigger the bidirectional component
A debug AOV lentil_debug is automatically created. The AOV will show the amount of bidirectional samples per pixel, with a closest filter.
Final checklist
The bidirectional sampling only kicks into action when:
- The AA samples are larger or equal to
3. - An imager of type:
lentil_imagerhas been added. - param: bidir_min_luminance is not
0. - param: bidir_sample_mult is not
0.