To create frit effect on glass you need to do the following.
- Create a gradient pattern as the first image attached on photoshop or other software and export as a PNG with transparent background.
- Open Rhino and create a new material under the “Physically Based” option
- Within the advanced setting of the physically based option go to “Opacity” and beside the “Amount” option select the three dots. Here you can import the image created in Step 1.
- Lower the Opacity amount under 90% and the frit should be less grainy.