result.xforms[i_img].start = result.nerf_matrix_to_ngp(result.xforms[i_img].start); result.xforms[i_img].end = result.nerf_matrix_to_ngp(result.xforms[i_img].end); 转换的代码是(对row进行交换的原因与后面要将的colmap2nerf.py的实现有关,这是坐标系反复变换的过程,但其实也可以修改一下...
(matrix, correct_pose, scale, offset): matrix[:, 0] *= correct_pose[0] matrix[:, 1] *= correct_pose[1] matrix[:, 2] *= correct_pose[2] matrix[:, 3] = matrix[:, 3] * scale + offset # cycle matrix = matrix[[1, 2, 0]] return matrix def poses_nerf2ngp(poses, correct...
if we multiply that direction vector with the rotation part of the transformation matrix (c2w[:3,-1]), it will give the direction of that pixel in 3D (rays_d). As thec2wis anidentity matrix, so thedirsare equal torays_d. For the position of pixels ...
Finally, to create the stereo training set, we generate a virtual set of stereo extrinsic pa- rameters S = I|b. The rotation is represented by the 3 × 3 identity matrix I and the translation vector b = (b, 0, 0)T has a magnitude b along the x axis in the camera reference ...
tlog::warning() << "Normalizing the matrix. This hints at an issue in your data generation pipeline and should be fixed.";dataset.xforms[i + first].start.block<3, 3>(0, 0) /= std::cbrt(xform.start.block<3, 3>(0, 0).determinant()); ...
Finally, to create the stereo training set, we generate a virtual set of stereo extrinsic parameters 𝐒=𝕀|𝐛. The rotation is represented by the 3×3 identity matrix 𝕀 and the translation vector 𝐛=(b,0,0)T has a magnitude b along the x axis in the camera reference system. ...
There are many controls in theinstant-ngpGUI. First, note that this GUI can be moved and resized, as can the "Camera path" GUI (which first must be expanded to be used). Recommended user controls ininstant-ngpare: Snapshot:use "Save" to save the trained NeRF, "Load" to reload. ...
InstantNGP通过这种改良,宣称能用5秒完成nerf的训练! Multiresolution Hash Encoding 以上就是哈希编码的简略过程,原文中使用的多分辨率哈希编码要多一些步骤。Plenoxels中的Coarse-to-fine策略是在训练中对grid进行上采样,而InstantNGP直接在最初就并存多分辨率的grid。
Since the matrix dimension of sampling points is low and is quite different from the number of channels in our network, we encoded the matrix to increase the dimension. The encoder 𝛾γ is 𝛾(𝑝𝑜𝑖𝑛𝑡)=(𝑝𝑜𝑖𝑛𝑡,sin(20𝜋𝑝𝑜𝑖𝑛𝑡),cos(20𝜋𝑝𝑜...
view_matrix是一个构造相机矩阵的的函数,输入是相机的Z轴朝向、up轴的朝向(即相机平面朝上的方向Y)、以及相机中心。输出下图所示的camera-to-world (c2w)矩阵。因为Z轴朝向,Y轴朝向,和相机中心都已经给定,所以只需求X轴的方向即可。又由于X轴同时和Z轴和Y轴垂直,我们可以用Y轴与Z轴的叉乘得到X轴方向。