I am currently playing around with Craft's built-in transform for WebP. I am using GD driver. In general I am able to generate WebP files from my assets. That works well. But it only works up to a specific target height of the transform.
format: webp / height: 500 / quality 100: = works
format: webp / height: 600 / quality 100 = doesn't work
format: webp / height: 600 / quality 10 = works
format: webp / height: 700 / quality 10 = doesn't work
Doesn't works mean, that I just see a white area instead of an image. Works mean, WebP was successfully generated and I can see it in the browser.
Any idea to get this thing running? It would be so awesome to be able to generate webp right out of Craft assets.