CN105677277A - Three-dimensional visualization section display method - Google Patents

Abstract

The invention provides a three-dimensional visualization section display method. The method comprises the following steps of 1, loading three-dimensional image data, obtaining the data size, obtaining the maximum value and the minimum value of each of x, y, z directions displayed by the three-dimensional image data, building an external cube of the three-dimensional image data according to the maximum and minimum values, and displaying the three-dimensional image data inside a three-dimensional data display frame; 2, obtaining section direction information of each coordinate axis direction, wherein the section direction is the center of the coordinate axis direction where a section is located, and obtaining the section direction information in real time and transmitting a value of the section direction information to the next step when a mouse is moved; 3, drawing rectangular areas on the two sides of a plane where the section position, wherein the rectangular areas are located between the external cube and the three-dimensional data display frame, and rendering the rectangular areas to a frame buffer object; 4, displaying the section. After the three-dimensional data is sliced, the comprehensive section direction information can still be obtained, the section is easy and convenient to operate and clear.

Description

A kind of three-dimensional visualization slice display method

Technical field

The invention belongs to technical field of nondestructive testing, particularly relate to a kind of three-dimensional visualization slice display method.

Background technology

Development along with industrial technology, successively Dynamic Non-Destruction Measurement has been carried out in industries such as boats and ships, space flight, weapons, chemical industry, coal, railways, apply this technology, can when large-scale, superior industrial devices be disassembled, observe the internal information of device, check internal flaw, improve the detection quality of device, reduce substandard products to a greater degree and come into the market. Along with deepening continuously of Dynamic Non-Destruction Measurement, the quality of large-scale important devices have also been obtained and improves constantly, and also strengthens the military capability of the country of China while improving China's industrial technology.

Industry CT is the one of Dynamic Non-Destruction Measurement, and it is to, under the detection undamaged condition of object, with the form of two-dimensional ct image or three-dimensional image, showing the structure within testee, composition, material and defect situation clearly, accurately, intuitively. In three-dimensional visualization, section display is a very important defect display function, and operator can according to section display, find out defect, simultaneously according to the slice location information on three-dimensional image, further determine that defect orientation, thus reaching more precisely defect recognition.

Realize from up-to-date GLSL (OpenGL renders language), 3 d image data can realize stereo display by ray-tracing algorithm, X-Y scheme Display Technique has rendered from traditional pipeline and has upgraded to pipeline able to programme and render, while improving rendering efficiency, also improve image displaying quality.

Tradition slice display technique depends on data image and shows, it may appear that dodge screen phenomenon; After data are cut, section viewing area can along with change, it is impossible to effectively show slice location information.

Summary of the invention

The shortcoming of prior art in view of the above, it is an object of the invention to provide a kind of three-dimensional visualization slice display method, is used for solving tradition slice display technique and there will be sudden strain of a muscle screen phenomenon, it is impossible to the problem effectively showing slice position.

The present invention provides a kind of three-dimensional visualization slice display method, comprises the following steps:

(1) 3 d image data is loaded, obtain the coordinate information of this data bulk portion, on the x, y, z direction that 3 d image data shows, obtain the maximin on each direction, set up the external cube of 3 d image data according to maximin, 3 d image data is shown in three-dimensional data display box;

(2) obtaining the section azimuth information of each change in coordinate axis direction, under original state, section orientation is the center of its place change in coordinate axis direction, during mobile mouse, obtains section azimuth information in real time, and its value is delivered to next step;

(3) in the drafting rectangular area, both sides in face, slice position place, rectangular area, between external cube and three-dimensional data display box, is rendered in frame buffer object by rectangular area simultaneously;

(4) 3 d image data is cut, carry out section display.

In described step (1), the equal proportion convergent-divergent principle of all directions is followed in the acquisition of maximin, first the length and width Pixel Information (length of picture is obtained when obtaining image data, width), secondly the quantity Loaded Image is set to elevation information, i.e. Z-direction information (height), finally by length and width scaled down to-1 to the interval of 1, height value value according to the above ratio zooms in and out, thus obtaining the maximin of Z-direction.

During rotated three dimensional view data, external cube can along with rotation, and the partial rectangular region that step (3) is drawn can be blocked, it is therefore desirable to judges whether that drafting is blocked in employing, it is judged that process is as follows:

When three-dimensional data just rotates to viewpoint it can be seen that during external another face cubical, be by blocking the critical point of drafting, calculating critical point angle α, computing formula is α=arccosL₁/L₀, wherein, L₀For the viewpoint distance to object center, L₁Minima for object center to this face;

The angle β between external cube each face and viewpoint is calculated to obverse unit vector according to the viewpoint unit vector to object center and object center, wherein, viewpoint is z-axis positive direction to the unit vector at object center, namely (0,0,1), the spin matrix that object center provides to obverse unit vector according to GLSL shading language obtains, and concrete calculating process is as follows: define according to vector productWherein,ForLength,For vectorLength, as shown from the above formula, angle can according to vector product formulaObtaining, when the length of vector is unit vector, viewpoint and obverse angle are $\mathrm{\β}=\arccos (\stackrel{\→}{a}\·\stackrel{\→}{b});$

When (β-α) >=0, carry out blocking drafting, during (β-α) < 0, carry out unshielding drafting.

As it has been described above, the present invention is according to section azimuth information, in the drafting rectangular area, both sides, face, slice position place of 3 d image data, according to the rectangular area drawn, it is possible to obtain following beneficial effect:

When 1, being operated by checking section, it is possible to by the discovery of rectangular area position more solid image on 3 d image data section face, place.

When 2, finding defect in section, according to the slice position in three dimensional display data, by cutting three-dimensional data, three-dimensional data can be checked further, analyzing defect information.

3, after three-dimensional data cutting, azimuth information of comprehensively cutting into slices can still be obtained so that sectioning is easy, clear.

Accompanying drawing explanation

Fig. 1 is shown as front display figure and view data schematic diagram.

Fig. 2 is shown rotated at showing figure and view data schematic diagram afterwards.

Fig. 3 rotates to the scene of critical point to look down schematic diagram.

Fig. 4 is critical point schematic diagram.

Fig. 5 is the flow chart of the present invention.

Detailed description of the invention

By particular specific embodiment, embodiments of the present invention being described below, those skilled in the art the content disclosed by this specification can understand other advantages and effect of the present invention easily.

As Figure 1-5, the present invention provides a kind of three-dimensional visualization slice display method, comprises the following steps:

(1) 3 d image data 2 is loaded, obtain the coordinate information of this data bulk portion, then on the x, y, z direction of 3 d image data 2 display, obtain the maximin on each direction, set up the external cube 4 of 3 d image data 2 according to maximin, 3 d image data 2 is shown in three-dimensional data display box 1.In described step (1), the equal proportion convergent-divergent principle of all directions is followed in the acquisition of maximin, first the length and width Pixel Information (length of picture is obtained when obtaining image data, width), secondly the quantity Loaded Image is set to elevation information, i.e. Z-direction information (height), finally by length and width scaled down to-1 to the interval of 1, height value value according to the above ratio zooms in and out, thus obtaining the maximin of Z-direction.

(2) obtaining the section azimuth information of each change in coordinate axis direction, under original state, section orientation is the center of its place change in coordinate axis direction, during mobile mouse, obtains section azimuth information in real time, and its value is delivered to next step.

(3) in the drafting rectangular area, both sides 3 in face, slice position place, rectangular area 3, between external cube 4 and three-dimensional data display box 1, is rendered in frame buffer object by rectangular area 3 simultaneously.

(4) 3 d image data is cut, carry out section display.

The present invention is according to section azimuth information, in the drafting rectangular area, both sides, face, slice position place of 3 d image data, according to the rectangular area drawn, it is possible to the more discovery section face, place of solid image; When section finds defect, according to the slice position in three dimensional display data, by cutting three-dimensional data, three-dimensional data can be checked further, analyzing defect information; After three-dimensional data cutting, still can obtain azimuth information of comprehensively cutting into slices so that sectioning is easy, clear.

During rotated three dimensional view data 2, external cube 1 can along with rotation, the rectangular area 3a that step (3) is drawn is blocked, 3b is visible, it is therefore desirable to judge whether to adopt the condition blocking drafting, it is judged that process is as follows: within the scope of the γ of visual angle, when three-dimensional data just rotates to viewpoint it can be seen that during external another face cubical, being by blocking the critical point of drafting, calculate critical point angle α, computing formula is α=arccosL₁/L₀, wherein, L₀For the viewpoint distance to object center, L₁Minima for object center to this face; The angle β between external cube each face and viewpoint is calculated to obverse unit vector according to the viewpoint unit vector to object center and object center, wherein, viewpoint is z-axis positive direction to the unit vector at object center, namely (0,0,1), the spin matrix that object center provides to obverse unit vector according to GLSL shading language obtains, and concrete calculating process is as follows: define according to vector productWherein,ForLength,For vectorLength, as shown from the above formula, angle can according to vector product formulaObtaining, when the length of vector is unit vector, viewpoint and obverse angle areWhen (β-α) >=0, carry out blocking drafting, during (β-α) < 0, carry out unshielding drafting. Operation angle of the present invention calculates priori conditions, whether rectangular image is blocked and has judged, the position of vivider display section.

Above-described embodiment is illustrative principles of the invention and effect thereof only, not for the restriction present invention. Above-described embodiment all under the spirit and category of the present invention, can be modified or change by any those skilled in the art. Therefore, art has usually intellectual such as modifying without departing from all equivalences completed under disclosed spirit and technological thought or change, must be contained by the claim of the present invention.

Claims (3)

1. a three-dimensional visualization slice display method, it is characterised in that comprise the following steps:

(1) 3 d image data is loaded, obtain the coordinate information of this data bulk portion, on the x, y, z direction that 3 d image data shows, obtain the maximin on each direction, set up the external cube of 3 d image data according to maximin, 3 d image data is shown in three-dimensional data display box;

(2) obtaining the section azimuth information of each change in coordinate axis direction, under original state, section orientation is the center of its place change in coordinate axis direction, during mobile mouse, obtains section azimuth information in real time, and its value is delivered to next step;

(3) in the drafting rectangular area, both sides in face, slice position place, rectangular area, between external cube and three-dimensional data display box, is rendered in frame buffer object by rectangular area simultaneously;

(4) 3 d image data is cut, carry out section display.

2. three-dimensional visualization slice display method according to claim 1, it is characterized in that: in described step (1), the equal proportion convergent-divergent principle of all directions is followed in the acquisition of maximin, first the length and width Pixel Information (length of picture is obtained when obtaining image data, width), secondly the quantity Loaded Image is set to elevation information, i.e. Z-direction information (height), finally by length and width scaled down to-1 to the interval of 1, height value value according to the above ratio zooms in and out, thus obtaining the maximin of Z-direction.

3. three-dimensional visualization slice display method according to claim 1, it is characterised in that:

During rotated three dimensional view data, external cube can along with rotation, and the partial rectangular region that step (3) is drawn can be blocked, it is therefore desirable to judges whether that drafting is blocked in employing, it is judged that process is as follows:

When three-dimensional data just rotates to viewpoint it can be seen that during external another face cubical, be by blocking the critical point of drafting, calculating critical point angle α, computing formula is α=arccosL₁/L₀, wherein, L₀For the viewpoint distance to object center, L₁Minima for object center to this face;

The angle β between external cube each face and viewpoint is calculated to obverse unit vector according to the viewpoint unit vector to object center and object center, wherein, viewpoint is z-axis positive direction to the unit vector at object center, namely (0,0,1), the spin matrix that object center provides to obverse unit vector according to GLSL shading language obtains, and concrete calculating process is as follows: define according to vector productWherein,ForLength,For vectorLength, as shown from the above formula, angle can according to vector product formulaObtaining, when the length of vector is unit vector, viewpoint and obverse angle are

When (β-α) >=0, carry out blocking drafting, during (β-α) < 0, carry out unshielding drafting.