Use case: stylized-concept
Asset type: alpha-channel image-clipping mask for RAITEC-inspired editorial image shapes.
Output: exactly one landscape 3:2 PNG with real alpha transparency, requested 1800 x 1200 pixels. Draw one single broad SOLID PURE WHITE convex polygon occupying central 80% of canvas, shaped like a landscape rectangle with large diagonal clipped upper-right and lower-left corners. This is a simple alpha mask: the entire polygon interior must be uniformly white and FULLY OPAQUE (alpha 255); everything outside must be FULLY TRANSPARENT (alpha 0). Smooth antialiased perimeter only, no internal holes, shadows, textures, gradients, borders, bevels, folds or linework. Sharp precise architecture-inspired silhouette, straight diagonal cut corners. No words, logos, symbols, watermark, checkerboard, opaque rectangular backdrop or photo. White shape must remain completely blank because a photograph will be clipped into its alpha channel later.