A Procedural Bump Map Generation Algorithm For Arbitrary 3D Profiles

In the process of 3D model cutting and rendering,real-time and realism are two important criteria to judge the quality of the virtual simulation system.The realism of 3D model rendering is not only reflected on the surface of the object,but also on the cutting profile.Although the 3D texture can simulate the color texture on the profile,it cannot store the normal perturbations directly.Since the color information is independent of the profile,while the normal information is related to the direction of the profile.And the 3D texture is difficult to obtain,complex in calculation and large in storage.Traditional 2D bump mapping stores surface normal perturbations into 2D texture.The normal information of any point inside the model cannot be calculated from the surface normal.So this method cannot be applied to any profile of 3D model.Therefore,a procedural bump mapping generation algorithm for any 3D profile is proposed.It incorporates the internal microstructure of the model to achieve the bump mapping effect on any profiles,improves the realism and immersion in the cutting simulation process.Moreover,it only takes about0.5 milliseconds to render a frame,which meets the need of real-time rendering during cutting operation.The specific research work is divided into the following aspects:Microstructure modeling based on noise texture perturbation.In this paper,sphere and cylinder are selected as the internal microstructure.Firstly,the microstructure of model is modeled.According to the interval between the microstructures,the position and size of each structure are obtained.And the microstructure with same size and structured position is obtained.Then based on the theory of Perlin noise and Worley noise,the corresponding noise texture is calculated respectively.Then use Worley noise to disturb the sphere structure,use Perlin noise to disturb the cylinder structure to get the irregular microstructure.Procedural bump mapping algorithm for any profile.In this paper,the corresponding bump mapping algorithms are proposed for sphere and cylinder respectively.The algorithm divides the profile into three cases: tearing,hollow cutting and solid cutting.In each case,according to the relationship between microstructure and profile,different mathematical models are used to calculate the normal perturbations.Then the disturbed normal is used to render the profile,the bump mapping rendering effect with microstructure on the profile is obtained.When cutting the flexible model,according to the deformation state of the model,the deformation gradient is calculated.Then disturbed normal is transformed from the undeformed state to the deformed state by using the deformation gradient.