o-voxel/src/convert/api.h

/*
 * O-Voxel Convertion API
 *
 * Copyright (C) 2025, Jianfeng XIANG <belljig@outlook.com>
 * All rights reserved.
 *
 * Licensed under The MIT License [see LICENSE for details]
 *
 * Written by Jianfeng XIANG
 */

#pragma once
#include <torch/extension.h>


/**
 * Extract flexible dual grid from a triangle mesh.
 *
 * @param vertices: Tensor of shape (N, 3) containing vertex positions.
 * @param faces: Tensor of shape (M, 3) containing triangle vertex indices.
 * @param voxel_size: Tensor of shape (3,) containing the voxel size in each dimension.
 * @param grid_range: Tensor of shape (2, 3) containing the minimum and maximum coordinates of the grid range.
 * @param face_weight: Weight for the face edges in the QEM computation.
 * @param boundary_weight: Weight for the boundary edges in the QEM computation.
 * @param regularization_weight: Regularization factor to apply to the QEM matrices.
 * @param timing: Boolean flag to indicate whether to print timing information.
 *
 * @return a tuple ((x, y, z), vertices, intersected, faces) containing the remeshed vertices and the corresponding voxel grid.
 */
std::tuple<torch::Tensor, torch::Tensor, torch::Tensor> mesh_to_flexible_dual_grid_cpu(
    const torch::Tensor& vertices,
    const torch::Tensor& faces,
    const torch::Tensor& voxel_size,
    const torch::Tensor& grid_range,
    float face_weight,
    float boundary_weight,
    float regularization_weight,
    bool timing
);


/**
 * Voxelizes a triangle mesh with PBR materials
 * 
 * @param voxel_size                    [3] tensor containing the size of a voxel
 * @param grid_range                    [6] tensor containing the size of the grid
 * @param vertices                      [N_tri, 3, 3] array containing the triangle vertices
 * @param normals                       [N_tri, 3, 3] array containing the triangle vertex normals
 * @param uvs                           [N_tri, 3, 2] tensor containing the texture coordinates
 * @param materialIds                   [N_tri] tensor containing the material ids
 * @param baseColorFactor               list of [3] tensor containing the base color factor
 * @param baseColorTexture              list of [H, W, 3] tensor containing the base color texture
 * @param baseColorTextureFilter        list of int indicating the base color texture filter (0: NEAREST, 1: LINEAR)
 * @param baseColorTextureWrap          list of int indicating the base color texture wrap (0: REPEAT, 1: CLAMP_TO_EDGE, 2: MIRRORED_REPEAT)
 * @param metallicFactor                list of float containing the metallic factor
 * @param metallicTexture               list of [H, W] tensor containing the metallic texture
 * @param metallicTextureFilter         list of int indicating the metallic texture filter (0: NEAREST, 1: LINEAR)
 * @param metallicTextureWrap           list of int indicating the metallic texture wrap (0: REPEAT, 1: CLAMP_TO_EDGE, 2: MIRRORED_REPEAT)
 * @param roughnessFactor               list of float containing the roughness factor
 * @param roughnessTexture              list of [H, W] tensor containing the roughness texture
 * @param roughnessTextureFilter        list of int indicating the roughness texture filter (0: NEAREST, 1: LINEAR)
 * @param roughnessTextureWrap          list of int indicating the roughness texture wrap (0: REPEAT, 1: CLAMP_TO_EDGE, 2: MIRRORED_REPEAT)
 * @param emissiveFactor                list of [3] tensor containing the emissive factor
 * @param emissiveTexture               list of [H, W, 3] tensor containing the emissive texture
 * @param emissiveTextureFilter         list of int indicating the emissive texture filter (0: NEAREST, 1: LINEAR)
 * @param emissiveTextureWrap           list of int indicating the emissive texture wrap (0: REPEAT, 1: CLAMP_TO_EDGE, 2: MIRRORED_REPEAT)
 * @param alphaMode                     list of int indicating the alpha mode (0: OPAQUE, 1: MASK, 2: BLEND)
 * @param alphaCutoff                   list of float containing the alpha cutoff
 * @param alphaFactor                   list of float containing the alpha factor
 * @param alphaTexture                  list of [H, W] tensor containing the alpha texture
 * @param alphaTextureFilter            list of int indicating the alpha texture filter (0: NEAREST, 1: LINEAR)
 * @param alphaTextureWrap              list of int indicating the alpha texture wrap (0: REPEAT, 1: CLAMP_TO_EDGE, 2: MIRRORED_REPEAT)
 * @param normalTexture                 list of [H, W, 3] tensor containing the normal texture
 * @param normalTextureFilter           list of int indicating the normal texture filter (0: NEAREST, 1: LINEAR)
 * @param normalTextureWrap             list of int indicating the normal texture wrap (0: REPEAT, 1: CLAMP_TO_EDGE, 2: MIRRORED_REPEAT)
 * @param mipLevelOffset                float indicating the mip level offset for texture mipmap
 * 
 * @return tuple containing:
 *   - coords: tensor of shape [N, 3] containing the voxel coordinates
 *   - out_baseColor: tensor of shape [N, 3] containing the base color of each voxel
 *   - out_metallic: tensor of shape [N, 1] containing the metallic of each voxel
 *   - out_roughness: tensor of shape [N, 1] containing the roughness of each voxel
 *   - out_emissive: tensor of shape [N, 3] containing the emissive of each voxel
 *   - out_alpha: tensor of shape [N, 1] containing the alpha of each voxel
 *   - out_normal: tensor of shape [N, 3] containing the normal of each voxel
 */
std::tuple<torch::Tensor, torch::Tensor, torch::Tensor, torch::Tensor, torch::Tensor, torch::Tensor, torch::Tensor>
textured_mesh_to_volumetric_attr_cpu(
    const torch::Tensor& voxel_size,
    const torch::Tensor& grid_range,
    const torch::Tensor& vertices,
    const torch::Tensor& normals,
    const torch::Tensor& uvs,
    const torch::Tensor& materialIds,
    const std::vector<torch::Tensor>& baseColorFactor,
    const std::vector<torch::Tensor>& baseColorTexture,
    const std::vector<int>& baseColorTextureFilter,
    const std::vector<int>& baseColorTextureWrap,
    const std::vector<float>& metallicFactor,
    const std::vector<torch::Tensor>& metallicTexture,
    const std::vector<int>& metallicTextureFilter,
    const std::vector<int>& metallicTextureWrap,
    const std::vector<float>& roughnessFactor,
    const std::vector<torch::Tensor>& roughnessTexture,
    const std::vector<int>& roughnessTextureFilter,
    const std::vector<int>& roughnessTextureWrap,
    const std::vector<torch::Tensor>& emissiveFactor,
    const std::vector<torch::Tensor>& emissiveTexture,
    const std::vector<int>& emissiveTextureFilter,
    const std::vector<int>& emissiveTextureWrap,
    const std::vector<int>& alphaMode,
    const std::vector<float>& alphaCutoff,
    const std::vector<float>& alphaFactor,
    const std::vector<torch::Tensor>& alphaTexture,
    const std::vector<int>& alphaTextureFilter,
    const std::vector<int>& alphaTextureWrap,
    const std::vector<torch::Tensor>& normalTexture,
    const std::vector<int>& normalTextureFilter,
    const std::vector<int>& normalTextureWrap,
    const float mipLevelOffset,
    const bool timing
);