Disclosure of Invention
The invention aims to solve the technical problem of providing a steep slope oblique photography model geological boundary optimization method by using a point migration technology, aiming at the characteristics of a water conservancy and hydropower engineering geological model, and optimizing the visualization process of geological boundary cataloging based on an oblique photography model by using a computer graphics principle and space geometric calculation so as to improve the quality and efficiency of field geological exploration.
In order to solve the technical problems, the invention adopts the technical scheme that: a steep slope oblique photography model geological boundary optimization method using a point migration technology comprises the following steps:
A. drawing exposed lines of the geological object on the oblique photography model in a multi-segment line drawing mode through point selection, and obtaining a three-dimensional coordinate sequence of points through the oblique photography model;
B. calculating a two-dimensional screen coordinate corresponding to the three-dimensional coordinate sequence in the step A;
C. encrypting the two-dimensional coordinates of the screen and the three-dimensional multi-segment lines at the corresponding positions of the oblique photography model;
D. carrying out micro offset on the three-dimensional coordinate points generated by encryption to enable the three-dimensional coordinate points to be higher than the earth surface by a micro distance;
E. and connecting all the shifted three-dimensional coordinate points, and giving color and line type information to form a geological boundary.
And D, drawing the multi-segment line in the step A in an absolute elevation mode.
The geological objects in the step A comprise stratigraphic boundary lines, lithologic boundary lines, fracture emergence lines, fold axes, physical geological phenomenon range lines, step boundary lines, stock ground range lines and fractures.
The encryption in the step C is to encrypt every coordinate selected in the drawing process, and the specific steps include:
C1. acquiring a screen two-dimensional coordinate of a current point, and further acquiring a space coordinate on a three-dimensional model corresponding to the screen coordinate;
C2. acquiring the space coordinate of the previous point, and calculating the corresponding screen two-dimensional coordinate in a reverse manner;
C3. averagely dividing a space line segment consisting of two space coordinate points into N-1 parts, and extracting corresponding N three-dimensional coordinate points (P)1,P2,…,PN);
C4. Connecting two-dimensional coordinates of the two screens to form a line segment, averagely dividing the line segment into N-1 parts, and extracting a series of corresponding two-dimensional coordinate points;
C5. obtaining a three-dimensional coordinate sequence (Q) corresponding to the two-dimensional coordinate point sequence corresponding to the previous step1,Q2,…,QN)。
The degree of encryption in steps C3 and C4 is determined by the scale of the extension of the drawn geological boundary, the computational power of the computer and the particular needs of the researcher.
The step D comprises the following steps:
D1. matching P in orderiAnd QiPoints, forming a point pair sequence;
D2. setting a limit value delta;
D3. each pair (P) is judgedi,Qi) If Q isiIs higher than PiIs greater than 5% of the total number of points, or Q is presentiAnd PiIf the distance between the two is greater than the limit value delta, the next step of offset is needed, otherwise, the offset is not needed;
D4. setting a small offset epsilon;
D5. each higher than PiQ of (2)iAlong a spatial straight line PiQiIs moved in the direction of (e);
D6. repeating D2-D4 until no more dot shifts are required;
D7. sequentially connecting the shifted (Q)1,Q2,…,QN) An optimized spatial geological boundary is formed.
And E, when the geological boundary formed by the construction in the step E is stored in a database, simultaneously warehousing the space coordinate sequences before and after the deviation so as to ensure the accuracy of the ground wire coordinate information and the rationality of visual display.
The invention has the beneficial effects that: the method has the advantages that the geological characteristics of the hydraulic and hydroelectric engineering and the limitation of the visual effect of the current GIS platform on the oblique photography model are considered, a visual optimization method is provided for the plotting process of the ground wire on the steep slope, the phenomenon that the ground wire is shielded under the condition that the ground surface is higher than the ground wire is avoided, the three-dimensional presentation effect of the ground wire is clearer, and the geological analysis can be effectively assisted.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work are within the scope of the present invention.
As shown in fig. 1, the method for optimizing a geological boundary of a steep slope oblique photography model by using a point offset technology comprises the following steps:
A. drawing exposed lines of the geological object on the oblique photography model in a multi-segment line drawing mode through point selection, and obtaining a three-dimensional coordinate sequence of points through the oblique photography model;
B. calculating a two-dimensional screen coordinate corresponding to the three-dimensional coordinate sequence in the step A;
C. encrypting the two-dimensional coordinates of the screen and the three-dimensional multi-segment lines at the corresponding positions of the oblique photography model;
D. carrying out micro offset on the three-dimensional coordinate points generated by encryption to enable the three-dimensional coordinate points to be higher than the earth surface by a micro distance;
E. and connecting all the shifted three-dimensional coordinate points, and giving color and line type information to form a geological boundary.
And D, drawing the multi-segment line in the step A in an absolute elevation mode.
The geological objects in the step A comprise stratigraphic boundary lines, lithologic boundary lines, fracture emergence lines, fold axes, physical geological phenomenon range lines, step boundary lines, stock ground range lines and fractures.
The encryption in the step C is to encrypt every coordinate selected in the drawing process, and the specific steps include:
C1. acquiring a screen two-dimensional coordinate of a current point, and further acquiring a space coordinate on a three-dimensional model corresponding to the screen coordinate;
C2. acquiring the space coordinate of the previous point, and calculating the corresponding screen two-dimensional coordinate in a reverse manner;
C3. averagely dividing a space line segment consisting of two space coordinate points into N-1 parts, and extracting corresponding N three-dimensional coordinate points (P)1,P2,…,PN);
C4. Connecting two-dimensional coordinates of the two screens to form a line segment, averagely dividing the line segment into N-1 parts, and extracting a series of corresponding two-dimensional coordinate points;
C5. obtaining a three-dimensional coordinate sequence (Q) corresponding to the two-dimensional coordinate point sequence corresponding to the previous step1,Q2,…,QN)。
The degree of encryption in steps C3 and C4 is determined by the scale of the extension of the drawn geological boundary, the computational power of the computer and the particular needs of the researcher.
The step D comprises the following steps:
D1. matching P in orderiAnd QiPoints, forming a point pair sequence;
D2. setting a limit value delta;
D3. each pair (P) is judgedi,Qi) If Q isiIs higher than PiIs greater than 5% of the total number of points, or Q is presentiAnd PiIf the distance between the two is greater than the limit value delta, the next step of offset is needed, otherwise, the offset is not needed;
D4. setting a small offset epsilon;
D5. each higher than PiQ of (2)iAlong a spatial straight line PiQiIs moved in the direction of (e);
D6. repeating D2-D4 until no more dot shifts are required;
D7. sequentially connecting the shifted (Q)1,Q2,…,QN) An optimized spatial geological boundary is formed.
And E, when the geological boundary formed by the construction in the step E is stored in a database, simultaneously warehousing the space coordinate sequences before and after the deviation so as to ensure the accuracy of the ground wire coordinate information and the rationality of visual display.
The encryption process in the step C is performed step by step in the drawing process, namely, encryption is performed once when one coordinate is selected, instead of uniform encryption after a plurality of complete segments of lines are drawn, so that the problem of inconsistent coordinate systems caused by dynamic rotation, movement or scaling of models is solved.
And E, the formed space multi-segment line is constructed for better visual presentation to assist space analysis, and the space coordinate sequences before and after the deviation are stored in a database at the same time to ensure the accuracy of the ground wire coordinate information and the rationality of visual display.
The invention improves the three-dimensional visualization effect when editing and recording the geological boundary on the oblique photography model.
The following is a detailed description in conjunction with an example:
the GIS platform adopted in this embodiment is a surfmapioobject 10 i. The method specifically comprises the following steps:
and A, drawing exposed lines of the geological object on the oblique photography model in a multi-segment line clicking and selecting mode. In general, a GIS platform provides a 'paste model' and an 'absolute elevation' quantity mode for space geometric objects such as points, lines and surfaces, wherein the 'paste model' means that the space geometric objects are vertically projected downwards along a Z axis onto an oblique photography model, and the 'absolute elevation' means that all coordinate points are directly connected in sequence in space to form a space multi-segment line. Where absolute elevation mode is required.
Line-type geological objects include stratigraphic boundaries, lithological boundaries, fracture reveal lines, fold axes, physical geological phenomenon range lines, step boundaries, stock ground range lines, and fissures.
And B, in the drawing process, acquiring screen coordinates of the points and a corresponding three-dimensional coordinate sequence in the oblique photography model by using a function of calculating the space coordinate points from the screen points, which is provided by a GIS platform.
C, encrypting the three-dimensional multi-segment lines of the screen coordinates and the corresponding positions of the oblique photography model, wherein the encryption process is performed step by step in the drawing process, and is not uniformly encrypted after the multi-segment lines are drawn, namely, each coordinate point is selected, and the encryption is performed sequentially, and the specific steps further comprise:
c1, acquiring a screen coordinate of a current point, and acquiring a space coordinate on a three-dimensional model corresponding to the screen coordinate by using a function of calculating a space coordinate point by the screen point;
step C2., obtaining the space coordinates of the previous point, and calculating the corresponding screen coordinates by using the function of "calculating screen points by using the space coordinates;
step C3. is to divide the space line segment composed of two space coordinate points into N-1 parts, and to extract the corresponding N three-dimensional coordinate points (P)1,P2,…,PN);
C4, connecting the two screen coordinates to form a line segment, averagely dividing the line segment into N-1 parts, and extracting a series of corresponding two-dimensional coordinate points;
the encryption rules in steps C3 and C4 are as follows:
(1) determining the distance between two spatial coordinate points and the pixel distance between two corresponding screen coordinate points;
(2) if the ratio of the two distances is within 100:1, encrypting at the distance of 2 meters;
(3) if the ratio of the two distances is between 100:1 and 200:1, encryption is carried out at a distance of 4 meters;
(4) if the ratio of the two distances is between 200:1 and 500:1, encryption is carried out at a distance of 10 meters;
(5) if the ratio of the two distances is between 500:1 and 1000:1, encryption is carried out at the distance of 20 meters;
(6) if the ratio of the two distances is between 1000:1 and 2000:1, encryption is carried out at the distance of 40 meters;
(7) if the ratio of the two distances is between 2000:1 and 5000:1, encryption is carried out at the distance of 100 meters;
(8) if the ratio of the two distances is 5000:1 to 10000:1, encryption is carried out at the distance of 200 meters;
(9) if the ratio of the two distances is between 10000:1 and 25000:1, encryption is carried out at the distance of 500 meters;
(10) if the ratio of the two distances is 25000:1 to 50000:1, encrypting at the distance of 1000 meters;
(11) if the ratio of the two distances is between 50000:1 and 100000:1, encryption is carried out at the interval of 2000 meters;
(12) if the ratio of the two distances is 100000:1 to 200000:1, the encryption is carried out at a distance of 4000 meters;
(13) if the ratio of the two distances is 200000:1 to 250000:1, encryption is carried out at a distance of 5000 meters;
step C5. obtains a three-dimensional space coordinate series (Q) corresponding to the two-dimensional coordinate point series corresponding to step C41,Q2,…,QN)。
And D, selectively carrying out micro offset on the three-dimensional coordinate point, wherein the specific steps comprise:
D1. matching P in orderiAnd QiPoints, forming a point pair sequence;
D2. setting a limit value delta;
D3. each pair (P) is judgedi,Qi) If Q isiIs higher than PiIs greater than 5% of the total number of points, or Q is presentiAnd PiIf the distance between the two is greater than the limit value delta, the next step of offset is needed, otherwise, the offset is not needed;
D4. setting a small offset epsilon;
D5. each higher than PiQ of (2)iAlong a spatial straight line PiQiIs moved in the direction of (e);
D6. repeating D2-D4 until no more dot shifts are required;
D7. sequentially connecting the shifted (Q)1,Q2,…,QN) Thus forming a space geological boundary with ideal visual effect.
The principle of the above-described adjustment process is shown in fig. 1.
And E, connecting all the shifted three-dimensional coordinate points, and assigning color and line type information to form a geological boundary line, as shown in figures 2A and 2B.
And finally, simultaneously importing the space coordinate sequences before and after the deviation into a database so as to ensure the accuracy of the ground wire coordinate information and the rationality of visual display.
The above-mentioned embodiments are only for illustrating the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to carry out the same, and the present invention shall not be limited to the embodiments, i.e. the equivalent changes or modifications made within the spirit of the present invention shall fall within the scope of the present invention.