| 71 | return P |
| 72 | |
| 73 | def getProjectionMatrix2(znear, zfar, K, W, H): |
| 74 | fx = K[0, 0] |
| 75 | fy = K[1, 1] |
| 76 | cx = K[0, 2] |
| 77 | cy = K[1, 2] |
| 78 | top = znear * cy / fy |
| 79 | bottom = -znear * (H - cy) / fy |
| 80 | right = znear * (W - cx) / fx |
| 81 | left = -znear * cx / fx |
| 82 | |
| 83 | P = torch.zeros(4, 4) |
| 84 | z_sign = 1.0 |
| 85 | |
| 86 | P[0, 0] = 2.0 * znear / (right - left) |
| 87 | P[1, 1] = 2.0 * znear / (top - bottom) |
| 88 | P[0, 2] = -(right + left) / (right - left) |
| 89 | P[1, 2] = (top + bottom) / (top - bottom) |
| 90 | P[3, 2] = z_sign |
| 91 | P[2, 2] = z_sign * zfar / (zfar - znear) |
| 92 | P[2, 3] = -(zfar * znear) / (zfar - znear) |
| 93 | |
| 94 | return P |
| 95 | |
| 96 | def fov2focal(fov, pixels): |
| 97 | return pixels / (2 * math.tan(fov / 2)) |