Material conversion method for three-dimensional model of power generation equipment

Abstract

The invention discloses a method for converting a three-dimensional model material of power generation equipment, which is used for converting all chartlets of a PBR into Blinn-Phong chartlets and comprises the following steps of: converting an HDRI panoramic chartlet of the PBR into a reflection chartlet; the PBR self-luminous chartlet is converted into a Gamma color space to serve as a luminous chartlet; performing positive film bottom overlapping operation on the PBR primary color chartlet and the ambient light shielding chartlet color to obtain a diffuse reflection chartlet color; converting the roughness map and the metallization map of the PBR into a highlight map; inverting the PBR opacity map color to obtain a transparency map color; and the normal map and the height map of the PBR material are processed and converted into the normal map. By means of the conversion method, cross-platform three-dimensional visualization real-time rendering can be conducted on the three-dimensional model of the generator set with high compatibility and low hardware requirements, parameter adjustment is convenient, and PBR material details can be reserved.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional visualization of power generation equipment, and particularly to a method for converting the PBR material of a three-dimensional model of high-end complex power generation equipment for three-dimensional visualization into a Blinn-Phong material. Background Art

[0002] The power generation equipment manufacturing industry is crucial for national security and economic development, and constitutes a key pillar of the country's electric power energy security. The digital transformation, intelligent development, and application of three-dimensional visualization technology in this industry play an important role in enhancing the country's comprehensive strength, achieving the energy conservation and emission reduction goals, and promoting the transformation and upgrading of the national energy structure.

[0003] High-end complex power generation equipment is a fundamental key equipment in the energy field, known for its numerous parts and complex structure. Constructing a three-dimensional visualization model and material of power generation equipment is crucial for realizing the three-dimensional visualization display of the equipment.

[0004] Due to the large amount of three-dimensional model data of power generation equipment, most in the industry consider using physically-based rendering (PBR) materials to represent the characteristics of equipment with finer granularity, such as using normal maps to represent screw threads and ambient occlusion maps to represent the shadow relationship between the mesh models of the equipment, to ensure that the accuracy of the model meets the requirements of actual applications without being overly simplified or overly complex. However, the rendering effect of the three-dimensional model of power generation equipment using PBR materials is restricted by the hardware device configuration on mobile and web platforms. It is difficult to achieve the rendering effect of the desktop and client sides, and at the same time, it reduces the real-time performance and smoothness of the three-dimensional scene, resulting in a poor user interaction experience.

[0005] The Blinn-Phong material is a model material rendered based on the empirical lighting model of diffuse reflection - specular highlight. It is still widely supported in the three-dimensional model rendering engine and platform of power generation equipment, and has good cross-platform compatibility; the calculation is relatively simple, without the need for complex textures and parameters, which can reduce resource consumption, improve rendering efficiency, increase the real-time performance of the system scene rendering and the smoothness of user interaction, and has good performance on resource-constrained platforms. However, Blinn-Phong is an empirical model-based lighting model, and its material has problems such as difficult parameter adjustment and insufficient details, reducing the rendering effect of the three-dimensional model and making it difficult to meet the requirements of actual applications. Summary of the Invention

[0006] To solve the above problems, the present invention proposes a method for converting the PBR material of a three-dimensional model of a power generation equipment into a Blinn-Phong material, which converts the PBR material of the three-dimensional model of the power generation equipment for the desktop into a Blinn-Phong material for the mobile / web end, compresses the quantity and size of the material texture maps, so that the three-dimensional model of the power generation equipment can accurately and realistically perform three-dimensional visualization under the condition of reasonable configuration of the display hardware device, meet the cross-platform compatibility, real-time performance and interactive fluency of the system, and greatly reduce the material resource production time and labor cost in the process of cross-platform transplantation of the three-dimensional visualization system of the power generation equipment.

[0007] The technical solution of the present invention is as follows:

[0008] The PBR material roughness / metallicity workflow texture maps of the three-dimensional model of the power generation equipment include eight texture maps: Basecolor, Opacity, Roughness, Metallic, Ambient Occlusion (AO), Emissive, Normal, and Height, which are used to represent the surface details of the three-dimensional model. The rendering adopts the Image-Based Lighting (IBL) technology, and the HDRI panoramic map is used to provide indirect lighting and reflection information.

[0009] The Blinn-Phong material with cross-platform advantages has five texture maps: Diffuse, Transparency, Specular, Emissive, and Normal to represent the surface details, and the Reflection texture map is used to provide the indirect lighting effect.

[0010] The rendering color of a certain point on the surface of the three-dimensional model of the power generation equipment is represented by Equation (1):

[0011] C o = fixed4((C a + C e + C d + C s ).rgb, C t .r) (1)

[0012] Where: C o is the output rendering color, which is an RGBA four-dimensional unit8 array;

[0013] C a is the ambient light color, C e is the emissive color, C d is the diffuse color, Cs For the highlight color, all are 3D RGB uint8 arrays;

[0014] C t For the transparency color, it is a 1D uint8 array.

[0015] Therefore, the method for converting PBR materials to Blinn-Phong materials starts from Equation (1). Based on the rendered color of the point model surface in the present invention, all texture channels of the PBR material are converted to Blinn-Phong materials. This method can be converted using image processing programs or software (such as Photoshop, OpenCV, etc.), or can be quickly batch-converted through GPU parallel computing (such as ComputeShader, etc.).

[0016] A method for converting the materials of a 3D model of a power generation equipment according to the present invention specifically comprises the following steps:

[0017] 1. Convert the HDRI panoramic texture of PBR to a Blinn-Phong reflection texture.

[0018] The HDRI panoramic texture of PBR is a high dynamic range (HDR) image with an aspect ratio of 2:1. Compress the width of the HDRI panoramic texture by 50%, and perform tone mapping using the ACES algorithm to convert the high dynamic range to a low dynamic range (LDR) as the Blinn-Phong material reflection texture.

[0019] 2. Convert the PBR self-illumination texture from the linear color space to the Gamma color space as the Blinn-Phong self-illumination texture.

[0020] Use the Cubic algorithm for conversion, that is, perform Gamma correction on the self-illumination texture in the linear space, as shown in Equation (2):

[0021]

[0022] Where: C e_g is the Blinn-Phong self-illumination texture color value in the Gamma color space, C e_l is the PBR self-illumination texture color value in the linear space; γ is the gamma value for the sRGB color space.

[0023] 3. Convert the PBR base color texture and the ambient occlusion texture to a Blinn-Phong diffuse texture.

[0024] Convert the PBR base color texture C b and the ambient occlusion texture color C AOPerform the multiply blend operation, that is, multiply pixel by pixel, and the result is used as the color C of the Blinn-Phong diffuse map d , to preserve the self-shadow effect of the material of the 3D model of the generator set, enhance the rendering texture, and the conversion process is shown in Equation (3):

[0025] C d = C b · k AO C AO m (3)

[0026] where: k AO is the shadow intensity factor, used to control the intensity of the shadow; m is the shadow contrast factor, used to control the contrast of the shadow.

[0027] 4.Convert the roughness map and metallic map of the PBR material into a Blinn-Phong specular map.

[0028] Convert the roughness map color C r to the specular color C smo , as shown in Equation (4):

[0029]

[0030] Use the metallic map color C m to perform linear interpolation to obtain the Blinn-Phong material specular map color C spec , as shown in Equation (5):

[0031] C spec = k DS + C m (C smo - k DS ) (5)

[0032] where: C smo is the specular color; k DS is the non-metallic reflection constant, k DS = [0.04, 0.04, 0.04].[[]END]

[0033] 5.Convert the opacity map of the PBR material into a Blinn-Phong transparency map.

[0034] Invert the PBR material opacity map color C opa , that is, subtract 1 from each pixel, and the result is used as the Blinn-Phong material transparency map color C t , as shown in Equation (6):

[0035] C t = 1 - C opa (6)

[0036] 6. Since the normal map and height map of the PBR material store different surface information of the model, the point normal vector and height information of the model surface are saved, which are used to deflect the incident light during lighting calculation. However, the Blinn-Phong material lighting model does not support the calculation of height information. Therefore, in order not to lose the details of the model surface, the PBR normal map and height map need to be processed before being converted into the Blinn-Phong normal map.

[0037] A normal map is an image in computer graphics that stores the normal vector information of the model surface. By rendering lighting reflection and scattering calculations, it deflects the incident light to create a more realistic light and shadow effect.

[0038] In this step, first, according to the height difference between a certain pixel (i, j) in the height map of the PBR material and its surrounding pixels, a binomial vector is constructed in the tangent space. And a tangent vector The normal vector is obtained by the cross product of the two vectors. Then, the normal vector calculated for the pixel (i, j) is normalized and packaged into a preliminary normal map pixel. The normal map pixel is the unit normal vector P of a certain point P on the object surface. N (x p , y p , z p ) After being compressed by the normal packaging algorithm and through the position of this point in the model's UV coordinates, it is written as a pixel of the normal map.

[0039] The calculation of the normal vector corresponding to the pixel (i, j) in the height map of the PBR material is shown in equations (7)-(9):

[0040]

[0041] Where: is the binomial vector of the pixel (i, j), is the tangent vector of the pixel (i, j), is the normal vector of the pixel (i, j); C h is the PBR height map color of the pixel (i, j), which is a unit8 one-dimensional grayscale vector, including C h (i + 1, j), C h (i - 1, j), C h (i, j + 1), C h (i, j - 1); x (i,j) , y (i,j) , z (i,j)The three components of the normal vector calculated for pixel (i, j).

[0042] Then, perform normalization (Normalize) and normal packaging (Normal Package) of the normal vector. If the target 3D visualization system uses the OpenGL API for rendering calculations, the G channel of the preliminary normal map color obtained through the above calculations in this step needs to be inverted to obtain the normal map color C suitable for OpenGL. N_OpenGL (i, j), the process is as shown in Equations (10)-(12):

[0043]

[0044] C N_OpengL C(i, j) = [C N (i, j).r, 1 - C N (i, j).g, C N (i, j).b] (12) Where: l N is the length of the normal vector, and C N (i, j) is the normal map pixel color of the pixel (i, j) to which the height map belongs.

[0045] Finally, perform normal unpacking (Normal Unpack) on the preliminary normal map converted from the height map of the PBR material and the normal map originally contained in the PBR material respectively, and perform normal combination (Normal Combine). The mixing and superposition algorithm for the normal combination can adopt algorithms such as the mixed partial derivative algorithm, linear mixing algorithm, superposition mixing algorithm, whitening mixing algorithm, or UDN mixing algorithm, etc. In the actual process, considering that the power generation equipment model is a hard surface model and the normal mutation is less, the mixed partial derivative algorithm (Partial Derivative, PD) is used for normal combination with the best effect.

[0046] For a certain pixel (i, j) in the preliminary normal map C1 converted from the height map and the normal map C2 in the PBR material, the calculation process is as shown in the following Equations (13)-(17).

[0047]

[0048] Where: is the normal vector calculated for the PBR height map, is the normal vector to which the PBR material belongs, is the normal vector after normal combination, is the normal vector of the length, and C c(i,j) is the Blinn-Phong normal map color value corresponding to the pixel (i,j) after conversion;

[0049] [x1, y1, z1] are the three components of the normal vector represented by a pixel in the first normal map (the normal map obtained by converting the height map); of;

[0050] [x2, y2, z2] are the three components of the normal vector represented by a pixel in the second normal map (the PBR material normal map); of;

[0051] [x c , y c , z c is the normal vector after mixing the normal information of the two normal maps; of the three components.

[0052] In the above calculations, r, g, and b respectively represent the red component / green component / blue component of a certain pixel, that is, the first / second / third digit of the pixel array, and the HLSL / GLSL shader language programming standard can be referred to.

[0053] In computer graphics, both vectors and colors are floating-point arrays of length 3 (float3 / vec3). The operation of taking components is equivalent, such as a.x and a.r. Similar operations also include (a.rg, a.xy / a.rgb, a.xyz), all of which represent taking the first component of the vector, and the HLSL / GLSL shader language programming standard can be referred to.

[0054] Through the above six steps, 8 texture maps and 1 panoramic map of the PBR material of the three-dimensional model of the generator set are converted into 6 texture maps of the Blinn-Phong material, enabling the three-dimensional model of the generator set to perform cross-platform three-dimensional visualization real-time rendering with high compatibility and low hardware requirements. The required material texture map resources are only two-thirds of those of the PBR material.

[0055] The technical effects of the present invention are mainly manifested in the following aspects:

[0056] This method can be applied to multiple rendering engines and platforms, and can effectively convert the materials of the three-dimensional model of power generation equipment, with good cross-platform compatibility;

[0057] On the basis of ensuring the real rendering of the three-dimensional model of the generator set, the rendering calculation of the Blinn-Phong material converted by this method is relatively simple, without the need for complex texture maps and parameters, which can reduce resource consumption, improve rendering efficiency, increase the real-time performance of the system scene rendering and the smoothness of user interaction, and has good performance on platforms with limited resources;

[0058] This method can retain the basic parameters of PBR materials during the conversion process, with simple adjustment and rich details. It takes into account the consistency of the cross-platform rendering effect of the 3D model of the generator set and can better meet the requirements of 3D visualization applications of the generator set. Brief Description of the Drawings

[0059] Figure 1 It is a comparison chart of the conversion of the PBR material texture map and the Blinn-Phong material texture map of the present invention.

[0060] Figure 2 It is a flowchart of the method of the present invention.

[0061] Figure 3 It is a comparison image of converting the material of the medium and low pressure cylinder model in the steam turbine generator set by using the present invention.

[0062] Figure 4-1 、 4-2 is corresponding to Figure 3 a screenshot of the terminal interface after the conversion of the model material texture map is completed. Detailed Embodiments

[0063] Embodiment

[0064] A method for converting the material of a 3D model of a power generation equipment according to the present invention, according to the rendering color of the surface of a certain point model of the power generation equipment, as Figure 1 shown, it is necessary to convert the texture map of the PBR material into the reflection texture map of the Blinn-Phong material, and the specific steps are as follows:

[0065] 1. Convert the HDRI panoramic texture map of PBR into a Blinn-Phong reflection texture map.

[0066] The HDRI panoramic texture map of PBR is an HDR image with an aspect ratio of 2:1. Compress the width of the HDRI panoramic texture map by 50%, and perform tone mapping using the ACES algorithm to convert the high dynamic range into a low dynamic range LDR as the Blinn-Phong material reflection texture map.

[0067] 2. Convert the PBR self-illumination texture map from the linear color space to the Gamma color space as the Blinn-Phong self-illumination texture map.

[0068] Use the Cubic algorithm for conversion, that is, perform Gamma correction on the self-illumination texture map in the linear space, as shown in Equation (2):

[0069]

[0070] Where: C e_gis the Blinn-Phong self-illumination map color value in the Gamma color space, C e_l is the PBR self-illumination map color value in the linear space; γ is the gamma value, used for the sRGB color space, with a value of approximately 2.2.

[0071] 3. Convert the PBR base color map and ambient occlusion map into a Blinn-Phong diffuse map.

[0072] Convert the PBR base color map C b and the ambient occlusion map color C AO perform a multiply operation, that is, multiply pixel by pixel, and the result is used as the Blinn-Phong diffuse map color C d , to retain the self-shadow effect of the three-dimensional model material of the generator set and enhance the rendering texture. The conversion process is shown in Equation (3):

[0073] C d = C b ·k AO C AO m (3)

[0074] where: k AO is the shadow intensity factor, used to control the intensity of the shadow; m is the shadow contrast factor, used to control the contrast of the shadow.

[0075] 4. Convert the roughness map and metallicity map of the PBR material into a Blinn-Phong specular map.

[0076] Convert the glossiness color C r through the roughness map color smo , as shown in Equation (4):

[0077]

[0078] Then use the metallicity color C m to linearly interpolate the non-metallic reflection constant k DS and the glossiness color C smo to obtain the Blinn-Phong material specular map color C spec , as shown in Equation (5):

[0079] C spec = k DS + C m (C a - k DS ) (5) where: k DS = [0.04, 0.04, 0.04].

[0080] 5. Convert the PBR opacity map to a Blinn-Phong transparency map.

[0081] Invert the color C of the PBR material opacity map opa by subtracting it from 1 pixel by pixel, and use the result as the color C of the Blinn-Phong material transparency map t , as shown in Equation (6):

[0082] C t = 1 - C opa (7)

[0083] 6. Normal map conversion: Since the PBR normal map and height map store different model surface information, both need to be processed and converted into a Blinn-Phong normal map.

[0084] First, convert the PBR height map to a preliminary normal map.

[0085] Specifically: Based on the height difference between a certain pixel (i, j) in the PBR height map and its surrounding pixels, construct the binormal vector and the tangent vector in the tangent space. The normal vector is obtained by taking the cross product of the two vectors Then normalize the normal vector calculated for the pixel (i, j) and package it into a preliminary normal map pixel.

[0086] The calculation of the normal vector corresponding to the pixel (i, j) in the PBR height map is shown in Equations (7)-(9):

[0087]

[0088] Where: is the binormal vector of the pixel (i, j), is the tangent vector of the pixel (i, j), is the normal vector of the pixel (i, j); C h (i + 1, j), C h (i - 1, j), C h (i, j + 1), C h (i, j - 1) belong to a group of the PBR height map color C h of the pixel (i, j), C h is a one-dimensional grayscale vector of unit8; x (i,j) , y (i,j) , z (i,j) are the three components of the normal vector calculated for the pixel (i, j).

[0089] Then, normalize the normal vector and pack the normals. If the target 3D visualization system uses the OpenGL API for rendering calculations, the G channel of the normal map color needs to be inverted to obtain the normal map color C suitable for OpenGL. N_OpenGL (i, j), and the calculation process is shown in equations (10)-(12):

[0090]

[0091] C N_OpenGL (i, j) = [C N (i, j).r, 1 - C N (i, j).g, C N (i, j).b] (12) where l N is the length of the normal vector, and C N (i, j) is the normal map pixel color of the pixel (i, j) belonging to the height map.

[0092] Finally, unpack the initial normal map obtained by converting the height map of the PBR material and the normal map contained in the PBR material itself respectively, and perform hybrid superposition using the PD algorithm, that is, normal blending.

[0093] For a certain pixel (i, j) in the texture map, the calculation process is as shown in the following equations (13)-(17).

[0094]

[0095] where: is the normal vector calculated from the PBR height map, is the normal vector belonging to the PBR material, is the normal vector after normal blending, is the normal vector 's length, and C c (i, j) is the Blinn-Phong normal map color value corresponding to the pixel (i, j) after conversion; [x1, y1, z1] are the three components of the normal vector represented by the pixel of the first normal map (the normal map obtained by converting the height map); [x2, y2, z2] are the three components of the normal vector represented by the pixel of the second normal map (the PBR material normal map); [x (i, j) is the Blinn-Phong normal map color value corresponding to the pixel (i, j) after conversion; [x1, y1, z1] are the three components of the normal vector represented by the pixel of the first normal map (the normal map obtained by converting the height map); [x2, y2, z2] are the three components of the normal vector represented by the pixel of the second normal map (the PBR material normal map); [x 's length, and C c ,y c ,z c are the three components of the normal vector after mixing the normal information belonging to the two normal maps. of the three components.

[0096] In the above steps, r, g, and b respectively represent the red component / green component / blue component of a certain pixel, that is, the first / second / third digit of the pixel array.

[0097] Through the above six steps, the eight texture maps and one panoramic map of the PBR material of the three-dimensional model of the generator set are converted into six texture maps of the Blinn-Phong material, enabling the three-dimensional model of the generator set to perform cross-platform three-dimensional visualization real-time rendering with high compatibility and low hardware requirements. The required material texture map resources are only two-thirds of those of the PBR material. Apply the above method to the use conversion of the medium and low pressure cylinder model material of the steam turbine generator set: as Figure 3 shown, the left side is the linear space rendering image under the PBR material, and the right side is the image rendered in the Gamma space of the Blinn-Phong material based on OpenGL after converting the PBR material texture map of the model to the Blinn-Phong material by this method. Corresponding Figure 3 to the medium and low pressure cylinder model material of the steam turbine generator set in, the process screenshot of converting the PBR material texture map to the Blinn-Phong material texture map according to this method is shown in Figure 4.

Claims

1. A method for converting material of a three-dimensional model of power generation equipment, characterized by: Convert all textures of the PBR material of the power generation equipment 3D model to textures of the Blinn-Phong material; The PBR material maps of the three-dimensional model of the power generation equipment include: (1) a base color map, an opacity map, a roughness map, a metalness map, an ambient occlusion map, a self-illumination map, a normal map, and a height map for expressing the surface details of the three-dimensional model, a total of eight maps; (2) an HDRI panorama map for providing indirect lighting and reflection information; The Blinn-Phong material maps include: (1) a diffuse map, a transparency map, a specular map, a self-illumination map, and a normal map for expressing surface details, a total of five maps; (2) a reflection map for providing indirect lighting effects; The process of converting the texture of the PBR material of the three-dimensional model of the power generation equipment into the texture of the Blinn-Phong material is as follows: Step 1: compress the width of the HDRI panorama map of the PBR material, and use the +ACES algorithm for tone mapping to convert the high dynamic range into a low dynamic range as the reflection map of the Blinn-Phong material; Step 2, convert the self-illumination map of the PBR material from the linear color space to the Gamma color space as the self-illumination map of the Blinn-Phong material; Step 3, perform a multiplication operation on the base color map of the PBR material and the color of the ambient occlusion map, that is, multiply them pixel by pixel, and the result is used as the diffuse map color of the Blinn-Phong material; Step 4, convert the roughness map color of the PBR material into a glossiness color, and then use the metalness map color of the PBR material to linearly interpolate the glossiness color to obtain the highlight map color of the Blinn-Phong material; Step 5, invert the opacity map color of the PBR material, and use the result as the transparency map color of the Blinn-Phong material; Step 6, first construct a binormal vector and a tangent vector in the tangent space according to the height difference between a certain pixel in the height map of the PBR material and its surrounding pixels, obtain a normal vector by the cross product of the two vectors, and then normalize and pack the obtained normal vector into a preliminary normal map pixel; then, normalize the normal vector and pack the normal to obtain a normal map color suitable for the target three-dimensional visualization system; finally, unpack the normals of the preliminary normal map and the normal map of the PBR material respectively, and then use the partial derivative mixing algorithm for mixing and superposition, that is, normal mixing, to obtain the normal map of the final Blinn-Phong material.

2. A method for converting material of a three-dimensional model of power generation equipment according to claim 1, characterized in that: In step 2, the self-luminous map of the PBR material is converted using the Cubic algorithm, as shown in formula (2): Where: C e_g is the color value of the Blinn-Phong self-illumination map in the Gamma color space, C e_l It is the color value of the PBR material self-illumination map in linear space; γ is the gamma value, which is used in sRGB color space.

3. A method for converting material of a three-dimensional model of power generation equipment according to claim 1, characterized in that: In step 3, when the base color map and ambient occlusion map of the PBR material are converted into a Blinn-Phong diffuse reflectance map, the specific conversion process is shown in formula (3): C d =C b ·k AO C AO m (3) Where: C d is the Blinn-Phong diffuse map color, C b is the base color map color of the PBR material, C AO is the ambient occlusion map color of the PBR material; k AO is the shadow intensity factor, which is used to control the intensity of the shadow; m is the shadow contrast factor, which is used to control the contrast of the shadow.

4. A method for converting material of a three-dimensional model of power generation equipment according to claim 1, characterized in that: In step 4, the process of converting the roughness map color of the PBR material to the glossiness color is shown in formula (4): Where: C smo To convert the glossiness color, C r Roughness map color.

5. The method for converting the material of a three-dimensional model of power generation equipment according to claim 4, characterized in that: In step 4, the linear interpolation process of the highlight map color of the Blinn-Phong material is obtained as shown in formula (5): C spec =k DS +C m (C smo -k DS ) (5) Where: C spec is the Blinn-Phong material specular map color, C m is the metalness map color, C smo is the gloss color; k DS is the non-metal reflection constant, k DS =[0.04,0.04,0.04].

6. A method for converting material of a three-dimensional model of power generation equipment according to claim 1, characterized in that: In step 5, the process of converting the Blinn-Phong material transparency map color is shown in formula (6): C t =1-C opa (6) Where: C t is the transparency map color of the Blinn-Phong material, C opa It is the opacity map color of the PBR material.

7. The method for converting material of a three-dimensional model of power generation equipment according to claim 1, characterized in that: In step 6, the normal vector of the corresponding pixel (i, j) in the height map of the PBR material is calculated as shown in equations (7)-(9): in: is the binormal vector of pixel (i,j), is the tangent vector of pixel (i,j), is the normal vector of pixel (i, j); C h is the PBR material height map color of pixel (i, j), which is a unit8 one-dimensional grayscale vector, including C h (i+1,j),C h (i-1,j),C h (i,j+1),C h (i,j-1); x (i,j) ,y (i,j) ,z (i,j) The three components of the normal vector calculated for pixel (i,j).

8. A method for converting material of a three-dimensional model of power generation equipment according to claim 7, characterized in that: In step 6, if the target 3D visualization system uses OpenGL API for rendering calculation, the G channel of the preliminary normal map color is inverted to obtain the normal map color suitable for OpenGL. The specific process is shown in equations (10)-(12): C N_OpenGL (i,j)=[C N (i,j).r,1-C N (i,j).g,C N (i,j).b] (12) Where: l N is the normal vector length of pixel (i, j), C N (i, j) is the normal map pixel color of the height map pixel (i, j), C N_OpenGL (i,j) is the normal map color suitable for OpenGL; r, g, b represent the red component / green component / blue component of pixel (i,j), respectively.

9. The method for converting material of a three-dimensional model of power generation equipment according to claim 1, characterized in that: In step 6, for a pixel (i, j) in the initial normal map converted from the height map and the normal map in the PBR material, the specific calculation process is shown in equations (13)-(17): Among them: C1 represents the preliminary normal map converted from the height map, and C2 represents the normal map in the PBR material; The normal vector calculated for the PBR height map, is the normal vector of the PBR material. is the normal vector after normal blending, is the normal vector Length, C c (i,j) is the Blinn-Phong normal map color value corresponding to the pixel (i,j) after the conversion; [x1,y1,z1] is the normal vector represented by the normal map pixel obtained by the height map conversion The three components of; [x2, y2, z2] is the normal vector represented by the normal map pixel of the PBR material The three components of c ,y c ,z c ] is the normal vector after the normal information of the two normal maps is mixed The three components of r, g, and b represent the red component / green component / blue component of the pixel (i, j) respectively.

10. The method for converting material of a three-dimensional model of power generation equipment according to claim 1, characterized in that: The conversion method uses Photoshop or OpenCV for conversion, or performs fast batch conversion through GPU parallel computing.

Images