| """Unlit orthographic raster evidence; bounding-box alignment is not registration.""" |
| import numpy as np |
|
|
|
|
| def rasterize(parts, bounds, shape, front): |
| height, width = shape |
| front = np.asarray(front, dtype=float) |
| right = -np.cross(front, [0, 0, 1]) |
| all_vertices = np.concatenate([p['vertices'] for p in parts]) |
| lo = np.array([(all_vertices @ right).min(), all_vertices[:, 2].min()]) |
| span = np.array([np.ptp(all_vertices @ right), np.ptp(all_vertices[:, 2])]) |
| if np.any(span <= 0): |
| raise ValueError('Degenerate projection bounds') |
| x0, y0, x1, y1 = bounds |
| rgb = np.full((height, width, 3), 220, dtype=np.uint8) |
| depth = np.full((height, width), -np.inf) |
| front_facing = np.zeros((height, width), dtype=bool) |
| covered = np.zeros((height, width), dtype=bool) |
| occluded = np.zeros((height, width), dtype=bool) |
| for part in parts: |
| vertices, faces, uvs, texture = [part[k] for k in ('vertices', 'faces', 'uvs', 'texture')] |
| mode = part.get('alpha_mode', 'OPAQUE') |
| if mode not in {'OPAQUE', 'MASK'}: |
| raise ValueError('Unsupported diagnostic alpha mode: ' + mode) |
| factor = np.asarray(part.get('base_color_factor', [1, 1, 1, 1]), dtype=float) |
| screen = np.c_[(vertices @ right - lo[0]) / span[0] * (x1-x0) + x0, |
| y1 - (vertices[:, 2] - lo[1]) / span[1] * (y1-y0)] |
| for face, uv in zip(faces, uvs, strict=True): |
| p = screen[face] |
| xmin, ymin = np.maximum(np.floor(p.min(0)).astype(int), 0) |
| xmax, ymax = np.minimum(np.ceil(p.max(0)).astype(int), [width-1, height-1]) |
| if xmin > xmax or ymin > ymax: |
| continue |
| xx, yy = np.meshgrid(np.arange(xmin, xmax+1), np.arange(ymin, ymax+1)) |
| d = (p[1,1]-p[2,1])*(p[0,0]-p[2,0])+(p[2,0]-p[1,0])*(p[0,1]-p[2,1]) |
| if abs(d) < 1e-12: |
| continue |
| a = ((p[1,1]-p[2,1])*(xx-p[2,0])+(p[2,0]-p[1,0])*(yy-p[2,1]))/d |
| b = ((p[2,1]-p[0,1])*(xx-p[2,0])+(p[0,0]-p[2,0])*(yy-p[2,1]))/d |
| bary = np.stack([a,b,1-a-b], axis=-1) |
| inside = (bary >= -1e-7).all(-1) |
| xx, yy, bary = xx[inside], yy[inside], bary[inside] |
| z = bary @ (vertices[face] @ front) |
| coords = bary @ uv |
| tx = np.clip(np.rint(coords[:,0]*(texture.shape[1]-1)).astype(int),0,texture.shape[1]-1) |
| ty = np.clip(np.rint((1-coords[:,1])*(texture.shape[0]-1)).astype(int),0,texture.shape[0]-1) |
| if mode == 'MASK': |
| visible = texture[ty, tx, 3] / 255 * factor[3] >= part.get('alpha_cutoff', .5) |
| xx, yy, z, tx, ty = xx[visible], yy[visible], z[visible], tx[visible], ty[visible] |
| previous = depth[yy, xx] |
| occluded[yy, xx] |= np.isfinite(previous) & (np.abs(previous-z)>1e-6) |
| keep = z > previous |
| xx, yy, z, tx, ty = xx[keep], yy[keep], z[keep], tx[keep], ty[keep] |
| |
| srgb = texture[ty, tx, :3].astype(float) / 255 |
| linear = np.where(srgb <= .04045, srgb / 12.92, ((srgb + .055) / 1.055) ** 2.4) |
| linear *= factor[:3] |
| corrected = np.where(linear <= .0031308, 12.92 * linear, |
| 1.055 * np.maximum(linear, 0) ** (1/2.4) - .055) |
| rgb[yy,xx] = np.clip(np.rint(corrected * 255), 0, 255).astype(np.uint8) |
| depth[yy,xx] = z |
| normal = np.cross(vertices[face[1]]-vertices[face[0]],vertices[face[2]]-vertices[face[0]]) |
| front_facing[yy,xx] = normal @ front > 0 |
| covered[yy,xx] = True |
| return dict(rgb=rgb, coverage=covered, front_facing=front_facing, occluded=occluded) |
|
|
