In a significant upgrade of the Customizer capabilities on Models @ MakeWithTech, you now can preview the impact of your parameter changes before queuing your custom model for rendering. The customizer previews are low-resolution snapshots of the model with the customizer parameters changes applied.
When viewing a preview, you have options to rotate or flip the image, and zoom will be available in future releases.
To experience previews, head over to the site. Select an OpenSCAD model from the MWT or Thingiverse directories and click on the customizer icon. You will see two new options: "Full Preview" and "Simplified Preview. " Most models will preview just fine with the full preview, but since the backend is optimized for speed, it is also limited to 30 seconds. If the preview cannot complete in 30 seconds, you will have the option to generate a simplified preview. For simplified previews, I force the value $fa to 60 and $fn to 15. Changing these special OpenSCAD quality variables significantly reduces the time to generate a PNG file.
Like the rendering queue, the previews use the actual OpenSCAD image with output set to PNG. Unfortunately, the current preview beta release only includes a limited number of fonts and no third-party modules.
As always, let me know what you think by heading to forum.makewithtech.com and posting your thoughts.