GPU并行计算加速的实时可视外壳三维重建及其虚实交互

GPU-Based Real-Time 3D Visual Hull Reconstruction and Virtual-Reality Interaction

针对现有的基于图像的三维重建方法难以实现真实物体的快速三维重建,无法满足虚实交互等应用需求的问题,提出一种基于GPU并行计算的实时三维重建及其虚实交互方法.首先把物体所在空间剖分成具有数据独立性的体素集合,结合可视外壳重建算法和精确行进立方体算法并行遍历每个体素得到体素状态序列;然后并行压缩体素状态序列得到非空体素集合,对非空体素进行并行三角形网格化,并利用图形硬件的多重纹理映射和可编程功能进行基于像素的纹理映射;最后假定虚拟物体的粒子为运动受限的拉格朗日流体粒子,重建物体网格顶点为流体边界,通过流体动力学方程的并行光滑粒子动力学方法求解来计算虚实交互.实验结果表明,该方法在GPU上进行完全并行求解,在32×32×32的空间剖分精度下,实现了实时三维重建和20帧/s左右的虚实交互计算,适用于计算机图形学和虚拟现实等领域中的虚实交互应用.

Image-based reconstruction is an important researching content of computer graphics and virtual reality.However,current methods are still difficult to achieve fast3D reconstruction of real objects to support virtual-reality applications.This paper presents a novel method to implement real-time3D reconstruction and virtual-reality based on GPU.First,we split the entire space of real objects into separate voxels,and checked thestate of each voxel by the combination of Visual Hull and Exact Marching Cube.Second,we compressed voxelstate sequence and triangularize the non-empty voxels collection in parallel,and then implemented pixel-basedtexture mapping by using multiple texture mapping and programmable functionality of graphics hardware.Third,the particles of virtual objects are assumed to be the motion-confined fluid particles,so the virtual-reality interactionsare computed by solving the fluid motion equation using parallel smoothed particle hydrodynamics.The resultsdemonstrate that the proposed method can achieve real-time3D reconstruction and virtual-reality interactionin20FPS under the space resolution of32×32×32,and satisfy the requirements of stability and efficiency in virtualreality and computer graphics.