Web-based IES format file-based light visualization method and system

Abstract

This invention discloses a web-based method and system for visualizing lights using IES format files. The method includes: parsing the IES format file to obtain discrete metering curves; interpolating the discrete metering curves to obtain continuous metering curves; mapping and normalizing the continuous metering curves to obtain a light field map; integrating the light field map into a web application; and during rendering on the web application, selecting and calculating incident light information from the light field map, using the Kajiya rendering equation and combining it with the incident light information to calculate and visualize the lighting fixture. This method and system enable the parsing of IES format files on a web application and utilize the parsed files to improve the visualization and rendering effects of lights.

Description

Technical Field

[0001] This invention belongs to the field of lighting visualization, specifically relating to a web-based IES format file lighting visualization method and system. Background Technology

[0002] The IES format is a standard developed by the Illuminating Engineering Society of North America (IESNA). It uses ASCII encoding to describe the light distribution curves of lighting fixtures, making it easier for manufacturers to describe the photometric information of their products. The standard was first established in 1986 (IES LM-63-1986) and revised twice, in 1991 and 1995 (IES LM-63-1991 and IES LM-63-1995).

[0003] Currently, there are already authoritative IES parsing tools on the market, such as DIALux, but there are no web-based parsing and display tools with similar capabilities. Currently, parsing IES files requires downloading DIALux, which is quite cumbersome.

[0004] Patent document CN108537874A discloses a method for automatically converting 3D lighting data to Unreal Engine 4, including: outputting all 3D lighting data as a text file in the 3D software; starting the Unreal Engine 4 engine; in Unreal Engine 4, reading the lighting data text and restoring the lighting coordinates, lighting type, lighting direction, lighting color, lighting intensity, and all attributes of various 3D software lights; reading the lighting tags and overwriting all original lighting parameters. This method is only suitable for converting 3D lighting parameters to Unreal Engine 4 for lighting creation and is not suitable for web-based lighting design.

[0005] Patent document CN102980744A discloses a method for measuring the light distribution curve of a light guide lighting system. This method primarily involves measuring the light intensity values ​​at various points within the system, plotting the light distribution curve based on these values, and simultaneously outputting an IES file (an electronic file format required for building a luminaire library) to obtain a complete description of the light distribution distribution of the system. However, it is unclear whether the light distribution curve obtained in this way can be configured for lighting design on a web-based platform. Even if it can, the rendering effect using this light distribution curve cannot be guaranteed. Summary of the Invention

[0006] In view of the above, the present invention provides a Web-based method and system for visualizing lights using IES format files, which can parse IES format files on the Web and improve the visualization rendering effect of lights by using the parsed files.

[0007] To achieve the above-mentioned objectives, an embodiment provides a web-based method for visualizing lights in IES format files, comprising the following steps:

[0008] Parse IES format files to obtain parsed files containing discrete photometric curves;

[0009] Interpolate discrete photometric curves to obtain continuous photometric curves;

[0010] The light field map is obtained by mapping and normalizing the continuous photometric curves on the graph.

[0011] The light field map is integrated into the web application. During web rendering, incident light information is selected and calculated from the light field map. The Kajiya rendering equation is used in conjunction with the incident light information to calculate and render the lamps, and the rendering results are visualized.

[0012] In one embodiment, the interpolation method used for the photometric curve includes linear interpolation and bicubic interpolation.

[0013] In one embodiment, the point values ​​corresponding to the vertical angle of 0-180 degrees of the continuous photometric curve are mapped onto the horizontal axis, and the point values ​​corresponding to the horizontal angle of 0-360 degrees are mapped onto the vertical axis to achieve the on-screen mapping of the photometric curve.

[0014] In one embodiment, normalizing the luminous intensity value corresponding to each angle of the photometric curve includes: compressing the maximum value of the luminous intensity values ​​corresponding to all angles to 1, and dividing the remaining luminous intensity values ​​by the maximum value to achieve normalization, which can compress each pixel to 4 bytes.

[0015] In one embodiment, the rendering of the lamp using the Kajiya rendering equation and incorporating incident light information includes:

[0016] Kajiya's rendering equation is:

[0017]

[0018] in, The emission direction at position x of the colored piece is The emitted light, The emission direction at position x of the colored piece is The light emitted outwards at that time The light at position x originates from the incident direction. To the direction of launch The reflectance ratio, It is the direction of incidence. The resulting attenuation of incident light It is the infinitesimal sum of the hemispheres along the incident direction. The incident direction at position x is The incident light, calculated using optical information, is represented as:

[0019]

[0020] Where Color is the given luminaire color RGB value divided by the RGB mean, and I is the luminous flux intensity of the given luminaire. c1 is the normalized value of the luminous intensity in the light field diagram, c2 is the coefficient for converting the optical unit nit to the screen brightness value, d is the distance from the lighting fixture to position x, and c1 is an additional constant used to restore the luminous intensity value and preserve other analytical information. The calculation formula is as follows:

[0021] c1 = Maximum luminous intensity value in the photometric curve / Luminous flux of each light source × Luminous intensity multiplier × Number of light sources.

[0022] To achieve the above-mentioned objectives, an embodiment provides a web-based IES format file-based light visualization system, comprising:

[0023] The parsing unit is used to parse IES format files to obtain parsed files containing discrete photometric curves;

[0024] The light field plotting unit is used to interpolate discrete photometric curves to obtain continuous photometric curves, and then perform on-map mapping and normalization on the continuous photometric curves to obtain the light field plot.

[0025] The rendering unit is used to integrate the light field map into the web interface. When rendering on the web interface, it selects and calculates the incident light information from the light field map, uses the Kajiya rendering equation and combines the incident light information to calculate and realize the rendering of the lamp and visualize the rendering results.

[0026] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0027] After parsing the IES format file to obtain discrete photometric curves, the photometric curves are interpolated, normalized, and a light field map is drawn. The luminous intensity values ​​contained in this light field map facilitate low-cost rendering on the web. During web rendering, the Kajiya rendering equation is used in conjunction with the incident light information calculated from the luminous intensity values ​​in the light field map to perform rendering calculations and visualize the rendering results. This method can achieve lightweight rendering in a rasterization system, with better rendering effects and finer details, achieving high-quality rendering effects comparable to offline rendering. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart of the Web-based IES format file light visualization method provided in the embodiment;

[0030] Figure 2 This is a schematic diagram illustrating the vertical angle, horizontal angle, length, width, and height of a lighting fixture in IES format provided in the embodiment.

[0031] Figure 3 This is a photometric curve plot provided in the embodiment;

[0032] Figure 4 This is a schematic diagram of the light field provided in the embodiment;

[0033] Figure 5 The example provides a rendered image obtained using a web-based IES format file light visualization method;

[0034] Figure 6 This is an offline rendered image provided in the embodiment. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of this invention.

[0036] Figure 1 This is a flowchart of a web-based IES format file-based light visualization method provided in this embodiment. For example... Figure 1 As shown in the embodiment, the web-based IES format file light visualization method includes the following steps:

[0037] Step 1: Parse the IES format file to obtain a parsed file containing discrete photometric curves.

[0038] The IES format file itself describes the information of the light field corresponding to the luminaire. In order to obtain the rendering result of the corresponding luminaire, it is first necessary to parse the data in the IES format file. Taking the IES LM-63-1995 revised in 1995 as an example, the meaning of each data item is explained.

[0039] Parse the IES format file, and the parsing result is shown as:

[0040] 00 IESNA:LM-63-1995

[0041] 01 <Keyword 1 keyword>

[0042] 02 <Keyword 2 keyword>

[0043] 03……

[0044] 04 <Keyword n keyword>

[0045] 05 TILT= <file-spec> or <include> or <none>Light output change caused by light source tilt = "File name reflecting light output change" or "Including the following light output change parameters" or "No light output change". Lines 06 - 09 appear if and only if TILT = INCLUDE.

[0046] 06 <lamp-to-luminaire geometry Position of the light source relative to the luminaire>

[0047] 07 <#of pairs of angles and multiplying factors Number of tilt angles>

[0048] 08 <angles Magnitude of the angles>

[0049]

[0050] 10 <#of lamps Number of light sources>; <lumens per lamp Luminous flux per light source> <candelamultiplier Multiplication factor of luminous intensity>; <#of vertical angles Number of vertical angles>; <#of horizontalangles Number of horizontal angles>; <photometric type Type of photometric curve>; <units type Type of unit>; <width Width of the light-emitting surface>; <length Length of the light-emitting surface> <height Height of the light-emitting surface> <00,00128>

[0051] 11 <ballast factor Ballast factor>; <future use Future use factor>; <inputwatts Input power>

[0052] 1 <vertical angles Sequence of vertical angles>

[0053] 13 <horizontal angles Sequence of horizontal angles>

[0054] 14 <candela values for all vertical angles at first horizontal angle Sequence of luminous intensity values for all vertical angles at the first row of horizontal angles>

[0055] 15 <candela values for all vertical angles at second horizontal angle Sequence of luminous intensity values for all vertical angles at the second row of horizontal angles>

[0056] 16……

[0057] 17 <Candela values for all vertical angles at nth horizontal angle Sequence of candela values for all vertical angles at the last horizontal angle>

[0058] Among them, the types of photometric curves in item No. 10 include three categories, namely C-type photometric curve, B-type photometric curve, and A-type photometric curve. The photometric measurement of lighting fixtures is completed by placing the luminous body at the center of an imaginary sphere and measuring the luminous intensity (unit: candela) of the grid points (photometric network) on the surface of the imaginary sphere. The direction of the light source axis relative to the direction of the imaginary sphere determines the type of photometric curve.

[0059] Figure 2 It is a schematic diagram of the expression of the vertical angle, horizontal angle, length, width, and height of lighting fixtures in the IES format file. Combined with Figure 2 , the C-type photometric curve is usually applied to building and road lighting. The polar axis of the photometric network coincides with the vertical axis of the lighting fixture, and the photometric plane of 0 - 180 degrees coincides with the long axis of the lighting fixture. The B-type photometric curve is usually applied to adjustable outdoor or sports venue lighting. The polar axis of the lighting fixture coincides with the wide axis, and the photometric plane of 0 - 180 degrees coincides with the vertical axis of the lighting fixture. The A-type photometric curve is usually applied to the headlights and signal lights of motor vehicles. The polar axis of the lighting fixture coincides with the long axis, and the photometric plane of 0 - 180 degrees coincides with the vertical axis of the lighting fixture.

[0060] The types of units in item No. 10 include feet and meters. The sequence of horizontal angles in item No. 13 enumerates the horizontal angles. For the C-type photometric curve, the first value is usually 0, and the last value may be one of the following values: 0: There is only one horizontal angle, and the lighting fixture is horizontally symmetric on each photometric plane; 90: The lighting fixture is symmetric in each quadrant; 180: The lighting fixture is horizontally symmetric about the photometric plane of 0 - 180 degrees; 360: The lighting fixture has no symmetry. If the lighting fixture is symmetric about the photometric plane of 90 - 270 degrees, then the first value is 90 degrees and the last value is 270 degrees.

[0061] For the A-type photometric curve and B-type photometric curve, if the lighting fixture is horizontally symmetric about the vertical reference plane, then the first horizontal angle is 0 degrees and the last horizontal angle is 90 degrees; if the lighting fixture is not horizontally symmetric about the vertical reference plane, then the first horizontal angle is -90 degrees and the last horizontal angle is 90 degrees.

[0062] Step 2, interpolate the discrete photometric curve to obtain a continuous photometric curve.

[0063] IES format files only provide discrete data, while the photometric grid is a smooth, continuous field. To obtain a continuous light field, the discrete photometric curves need to be interpolated, using methods such as linear interpolation and bicubic interpolation. Here, we will use linear interpolation as an example to explain the specific technical details.

[0064] In the process of measuring and plotting photometric curves, measurement errors may occur, introducing extreme values ​​and causing the final data results to deviate from reality. Therefore, these extreme values ​​need to be removed when actually analyzing the file. For example, observe the candela values ​​corresponding to angles of 32.50°, 34.28°, and 35.00°, which are 5209.38, 6038.93, and 4533.49 respectively. A large abrupt change occurs within a very small angle range. If this abrupt value is directly used for plotting, it will result in unnatural bright streaks in the rendered image. Therefore, special processing is required. The processing method is as follows:

[0065] First, linear interpolation is used to sample the original data to obtain 181 data points: 0°, 1°, ..., 180°. Then, linear interpolation is used to sample these 181 data points to obtain the values ​​on a continuous, arbitrary photometric grid. For example, to obtain the metering value for rendering at 32.50°, we need to obtain the candela values ​​at 32° and 33°. To obtain the value at 32°, we use linear interpolation to obtain the original data corresponding to 27.50° and 32.50°, which are 5209.38 and 6038.93 candela respectively. Therefore, the value for 32° is 5209.38 + (6038.93 - 5209.38) / (32.50 - 27.50) * (32.00 - 27.50) = 5955.975 candela. Similarly, the metering value for 33° is 6461.806 candela. Interpolating the metering values ​​at 32° and 33° again yields the data for 32.5° as 6208.89 candela, which is larger than the original data of 5209.38 candela, making the metering smoother. Figure 3 As shown, the black dots are the original data points in the IES format file, and the curve on the right is the metering curve obtained using linear interpolation. It can be seen that the metering curve obtained by interpolation does not pass through all the data points, but connects the metering grid more smoothly, thus obtaining a more ideal rendering result.

[0066] Step 3: Map and normalize the continuous photometric curves to obtain the light field map.

[0067] By parsing the IES format file and interpolating the metering curves, all the necessary information for drawing the complete IES luminaire has been obtained, namely, the nit value (nits are the unit of brightness) corresponding to any point in space. However, for real-time rendering, directly parsing and interpolating from the IES format file for each drawing is too costly. Therefore, this embodiment needs to pre-calculate the parsing and interpolation process, mapping the result of the metering mesh pre-calculation onto a two-dimensional image (light field map) to reduce the amount of real-time calculation. Actual testing comparing the results with offline rendering showed that compressing the 3D metering mesh to 181 (horizontal axis pixels) * 360 (vertical axis pixels) * 4 (bytes / pixel) = 255KB achieves real-time results that closely approximate offline rendering results. Specifically, this involves mapping continuous metering curves onto the image, including mapping the continuous metering curves to... Figure 2 The 181 values ​​of vertical angle 0-180 degrees are mapped onto the horizontal axis of the light field diagram, and the 360 ​​values ​​of horizontal angle 0-360 degrees are mapped onto the vertical axis of the light field diagram.

[0068] To compress the data of each pixel to 4 bytes, the luminous intensity value in candela for each angle needs to be normalized. To ensure the highest possible accuracy, the maximum value of the luminous intensity for each angle is compressed to 1, and the remaining luminous intensity values ​​are divided by the maximum value to achieve normalization. The resulting light field map is shown below. Figure 4 As shown.

[0069] In this embodiment, in addition to normalizing the light field diagram, an additional constant is calculated to restore the luminous intensity value and save other analytical information. The other analytical information includes the luminous flux (lumens) of each light source, the multiplier factor of the luminous intensity, and the number of light sources. The calculation method of the additional constant includes: c1 = maximum luminous intensity value (candela) in the photometric curve / luminous flux (lumens) of each light source × multiplier factor of the luminous intensity × number of light sources.

[0070] Example data: c1 = 8564.0 / 13172.61 × 1.0 × 1.0 = 0.6501369128821092 solid angle^(-1).

[0071] Step 4: Integrate the light field map into the web application. When rendering on the web application, select and calculate the incident light information from the light field map, use the Kajiya rendering equation and combine it with the incident light information to calculate and realize the rendering of the lamp and visualize the rendering results.

[0072] In this embodiment, integrating the light field map into the web interface enables high-quality lighting fixture rendering on the web. Specifically, the Kajiya rendering equation is used for rendering calculations.

[0073]

[0074] in, The emission direction at position x of the colored piece is The emitted light, The emission direction at position x of the colored piece is The light emitted outwards at that time The light at position x originates from the incident direction. To the direction of launch The reflectance ratio, It is the direction of incidence. The resulting attenuation of incident light It is the infinitesimal sum of the hemispheres along the incident direction. The incident direction at position x is The incident light is represented as:

[0075]

[0076] Where Color is the given luminaire color RGB value divided by the RGB mean, and I is the luminous flux intensity of the given luminaire. c1 is the normalized value of the luminous intensity in the light field diagram, c2 is the coefficient for converting the optical unit nit to the screen brightness value, using 2.1e-3, with the unit being solid angle^(-1), d is the distance from the lighting fixture to position x, and c1 is an additional constant used to restore the luminous intensity value and save other analytical information.

[0077] The lighting fixture rendering obtained using the web-based IES format file lighting visualization method provided above is as follows: Figure 5 As shown, the offline rendering of the lighting fixture is as follows: Figure 6 As shown, comparison Figure 5 and Figure 6 As can be seen, the lamp rendering image obtained by using this method on the web is very close to the lamp rendering image obtained by offline rendering.

[0078] Based on the same inventive concept, the embodiment also provides a web-based IES format file light visualization system, including:

[0079] The parsing unit is used to parse IES format files to obtain parsed files containing discrete photometric curves;

[0080] The light field plotting unit is used to interpolate discrete photometric curves to obtain continuous photometric curves, and then perform on-map mapping and normalization on the continuous photometric curves to obtain the light field plot.

[0081] The rendering unit is used to integrate the light field map into the web interface. When rendering on the web interface, it selects and calculates the incident light information from the light field map, uses the Kajiya rendering equation and combines the incident light information to calculate and realize the rendering of the lamp and visualize the rendering results.

[0082] It should be noted that the Web-based IES format file light visualization device provided in the above embodiments should be illustrated using the above-described division of functional units. The functions can be assigned to different functional units as needed, i.e., the internal structure of the terminal or server can be divided into different functional units to complete all or part of the functions described above. Furthermore, the Web-based IES format file light visualization device and the Web-based IES format file light visualization method embodiments belong to the same concept; their specific implementation process is detailed in the Web-based IES format file light visualization method embodiments, and will not be repeated here.

[0083] The specific embodiments described above illustrate the technical solution and beneficial effects of the present invention in detail. It should be understood that the above description is only the most preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.< / none> < / include> < / file-spec>

Claims

1. A method for light visualization of IES format files based on Web, characterized in that, The method comprises the following steps: parsing an IES format file to obtain a parsed file containing discrete photometric curves; interpolating the discrete photometric curves to obtain continuous photometric curves; mapping the continuous photometric curves onto a graph and performing normalization processing to obtain a light field graph; wherein the mapping onto the graph comprises: mapping point values corresponding to a vertical angle of 0-180 degrees of the continuous photometric curves onto a horizontal axis, and then mapping point values corresponding to a horizontal angle of 0-360 degrees onto a vertical axis; the normalization processing comprises: compressing a maximum value of light intensity values corresponding to all angles into 1, and dividing the remaining light intensity values by the maximum value to achieve normalization, which can compress each pixel to 4 bytes; integrating the light field graph into a Web end, selecting and calculating incident light information from the light field graph when rendering in the Web end, and using a Kajiya rendering equation combined with the incident light information to calculate, render and visualize the rendering result of a lamp; the Kajiya rendering equation is: wherein, is the outgoing light at position x of the colored sheet with an outgoing direction , is the outgoing light at position x of the colored sheet with an outgoing direction , is the reflection ratio of light at position x from an incoming direction to an outgoing direction , is the incoming light attenuation caused by an incoming direction , is the infinitesimal sum of the incoming direction hemisphere, is the incoming light at position x with an incoming direction , which is calculated from the light information and is expressed as: where Color is the given luminaire color RGB value divided by the RGB mean value, I is the luminous intensity of the given luminaire, is the normalized value of the luminous intensity value in the light field map, c2is the coefficient of the conversion from the photometric unit nits to the screen luminance value, d is the distance of the lighting luminaire to the position x, and c1is an additional constant used to restore the luminous intensity value and preserve other analytical information, the calculation formula being: c1=(maximum light intensity value in the photometric curve x light intensity multiplier factor) / (luminous flux of each light source x number of light sources).

2. The web-based IES format file light visualization method of claim 1, wherein, The interpolation method used in the photometric curve includes linear interpolation and bicubic interpolation.

3. A web-based IES format file light visualization system, characterized by, The method comprises: a parsing unit configured to parse an IES format file to obtain a parsed file containing discrete photometric curves; a light field graph drawing unit configured to, after interpolating the discrete photometric curves to obtain continuous photometric curves, map the continuous photometric curves onto a graph and perform normalization processing to obtain a light field graph; wherein the mapping onto the graph comprises: mapping point values corresponding to a vertical angle of 0-180 degrees of the continuous photometric curves onto a horizontal axis, and then mapping point values corresponding to a horizontal angle of 0-360 degrees onto a vertical axis; the normalization processing comprises: compressing a maximum value of light intensity values corresponding to all angles into 1, and dividing the remaining light intensity values by the maximum value to achieve normalization, which can compress each pixel to 4 bytes; a rendering unit configured to integrate the light field graph into a Web end, select and calculate incident light information from the light field graph when rendering in the Web end, and use a Kajiya rendering equation combined with the incident light information to calculate, render and visualize the rendering result of a lamp; the Kajiya rendering equation is: wherein, is the outgoing light at position x of the colored sheet with an outgoing direction , is the outgoing light at position x of the colored sheet with an outgoing direction , is the reflection ratio of light at position x from an incoming direction to an outgoing direction , is the incoming light attenuation caused by an incoming direction , is the infinitesimal sum of the incoming direction hemisphere, is the incoming light at position x with an incoming direction , which is calculated from the light information and is expressed as: where Color is the given luminaire color RGB value divided by the RGB mean value, I is the luminous intensity of the given luminaire, is the normalized value of the luminous intensity value in the light field map, c2is the coefficient of the conversion from the photometric unit nits to the screen luminance value, d is the distance of the lighting luminaire to the position x, and c1is an additional constant used to restore the luminous intensity value and preserve other analytical information, the calculation formula being: c1=(maximum light intensity value in the photometric curve x light intensity multiplier factor) / (luminous flux of each light source x number of light sources).

Images