ND Variant Preview Selector

Shows a batch of images with thumbnails and lets you pick a variant (click or arrow keys). It is not an upscaler: the optional Upscale button sends the selected variant to the upscale branch you build after it (any upscale nodes, also third-party ones). Input: one parameters wire with the fields 'images' (the batch) and optionally 'image' (the upscaled result) - connect a Pack Parameters and it creates these inputs. Output: one parameters wire with 'multi_variant', 'selected_index' (0-based) and 'upscale' (True only for a run started by the Upscale button) - open it with Unpack Parameters. The gear button sets the file names, the saving of the variants and whether the Upscale button is shown; without it every batch is saved.