JP4372282B2 - Parametric mapping apparatus and parametric mapping method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a field of three-dimensional computer graphics using polygons (polygons), and relates to a mapping apparatus and mapping method for attaching various information to a polygon surface.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image processing apparatus that performs rendering processing (rendering) in 3DCG (3 Dimensional Computer Graphics) 3D information such as texture mapping, reflection mapping, bump mapping, hue mapping, multi-texture mapping, etc. When mapping is desired, the mapping is performed directly through perspective transformation, interpolation along the contour, interpolation along the scanning line, and inverse perspective transformation.
[0003]
[Problems to be solved by the invention]
In a conventional 3DCG drawing apparatus, information (mapping variable) to be mapped is at most about texture coordinates and diffuse luminance. However, in recent 3DCG drawing, techniques such as reflection mapping, bump mapping, hue mapping, and multi-texture mapping become common, and if these are mapped separately, the hardware and software resources become enormous. It came out.
[0004]
The present invention has been made to solve the above-described problems, and an object thereof is to obtain a parametric mapping apparatus and a parametric mapping method for simplifying hardware and software resources for performing various mappings. To do.
[0005]
[Means for Solving the Problems]
The parametric mapping device according to claim 1 of the present invention is a mapping device for mapping mapping variables onto each pixel, and means for mapping a parameter to a pixel constituting a polygon instead of various mapping variables. To the mapping variable to be mapped onto each pixel constituting the polygon from the parameter mapped on each pixel constituting the polygon expressed using the mapping variable on each vertex of the polygon. It is characterized by having means for executing mapping by using a predetermined conversion formula.
[0006]
The parametric mapping device according to a second aspect of the present invention is the parametric mapping device according to the first aspect, wherein the mapping variable is a variable given for each vertex of the polygon and is obtained from data given for each vertex. There are two variables to be distributed to all the pixels on the polygon, and the parametric variable has a parametric plane, and the parametric (u, v) value on each vertex and each vertex Between the values of the mapping variable T above, the linear expression T (u, v) = a + b · u + c · v + d · u · v (a, b, c, d are constants)
And the values of the parametric variables on each vertex are arranged on a straight line or overlapped on a point when they are displayed on the parametric plane, so that the sides cross each other instead of being in a zero area state. It is characterized by being pre-selected so as not to be in a twisted figure state.
[0007]
A parametric mapping method according to the invention of claim 3 is a mapping method for mapping mapping variables onto each pixel, wherein a parameter is mapped to pixels constituting a polygon instead of various mapping variables; Predetermined to the mapping variable to be mapped onto each pixel constituting the polygon from the parametric variable mapped onto each pixel constituting the polygon expressed using the mapping variable on each vertex of the polygon It has the process of performing mapping by using a conversion formula.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The feature of each embodiment described below is that, in order to perform mapping, instead of various mapping variables such as texture coordinates, normal vectors, hues, diffuse luminance, and opacity, a mediation that is a virtual parameter representing them all. The variable is mapped to the pixels constituting the polygon, and the polygon is constructed from the parameter variable mapped on each pixel constituting the polygon, expressed using the mapping variable on each vertex of the polygon. Mapping variables such as texture coordinates, normal vector, hue, diffuse luminance, and opacity on each pixel constituting the polygon using a conversion formula (bilinear interpolation formula) to the mapping variable to be mapped on each pixel. By constructing such that the value of Is the ability to simplify hardware and software resources to only have mapping only parametric compared with the case of mapping the number separately. Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0009]
Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a functional block diagram for explaining a drawing circuit 100 according to an embodiment of the present invention. In FIG. 1, 100 is a drawing circuit, 110 is a geometry processor, 120 is a polygon processor, 121 is a Z buffer, 122 is a paint RAM, 130 is a parametric mapping device, 131 is a texture memory, 132 is an attribute memory, and 140 is a frame processor. , 150 is a two-dimensional display processor, ARGB is selected texture color data, Fd is a data identification flag, Tc is data specifying a texture color (texture color data), and (Tx, Ty) is data specifying texture coordinates (texture coordinates) Data) and DX indicate data for specifying the X-direction component (horizontal direction component) of the display coordinates. Referring to FIG. 1, a drawing circuit 100 according to the present embodiment is a processor that performs 3DCG (3 Dimensional Computer Graphics) drawing processing, and each pixel has a Z coordinate (depth on the screen). Z buffer 121 that is a memory that holds information) and is used for hidden surface processing, and data DX that specifies the X-direction component (horizontal direction component) of the display coordinates that express (model) the three-dimensional shape by executing geometry transformation the geometry processor 110 generates and outputs, a paint RAM122 to retain data in the order to choose preferentially more before the pixel, more forward from the Z-coordinate (depth information) and paints RAM122 per pixel from the Z buffer 121 See data for preferential selection of pixels A polygon processor 120 that generates and outputs texture coordinate data (Tx, Ty) for specifying the polygon 50 (to be described later), a data identification flag Fd, and polygon data (data for specifying the polygon 50), and texture coordinate data (Tx, Ty). ) To specify the texture memory 131 externally attached to the parametric mapping device 130 in order to hold the texture color data Tc, which is color data, and data specifying attributes (attributes) as various additional information for the texture. Attribute memory 132 to be held, texture color data Tc from the externally attached texture memory 131, data specifying the attribute from the attribute memory 132, text from the polygon processor 120 Rendering and color calculation processing, environment mapping processing, color calculation processing, mirror surface with reference to coordinate data (Tx, Ty) and data DX specifying the X direction component (horizontal direction component) of display coordinates from geometry processor 110 A parametric mapping device 130 that generates and outputs selected texture color data ARGB by executing reflection processing and opacity processing, polygon data from the polygon processor 120, and selected texture color data ARGB from the parametric mapping device 130 A frame processor 140 that generates and outputs image data for two-dimensional display that performs image composition processing with reference to the image, and two-dimensionally displays the image data for two-dimensional display from the frame processor 140 to the display means (CRT). 2D image display The display processor 150 is mainly configured.
[0010]
Next, the operation (parametric mapping method) of the parametric mapping apparatus 130 in FIG. 1 will be described. First, parameters that are mapped onto the polygon 50 on the XY plane (display coordinate plane) are set as parameters (u, v). Mapping variables T (u, v) include texture coordinates (Tx, Ty), normal vector of polygon surface, hue, diffuse luminance, opacity, and the like. Further, in the present embodiment, in order to simplify the interpolation calculation, the parameter of the vertex A (first vertex) parameter (u, v) = (0, 0) and the vertex B (second vertex) are mediated. Variable (u, v) = (0, 1), parametric variable (u, v) = (1, 1) of vertex C (third vertex), parametric variable (u, v) of vertex D (fourth vertex) v) = (1, 0), but there is no particular limitation, and the parametric variables (u, v) are the vertex A (first vertex) and vertex B (second vertex) of the polygon 50. , When the values at the vertex C (third vertex) and the vertex D (fourth vertex) are displayed on the uv plane (parametric variable plane), the vertex A (first Vertex), Vertex B (Second Vertex), Vertex C (Third Vertex), Vertex D (Fourth Vertex) are connected by line segments. Zero Only it needs to be pre-selected to also joined along their edges rather than state is not in a state of twisted figure crossed.
[0011]
Since the values on the vertices of u and v, which are parametric variables, have been determined, the parametric variables (u, v) on all the pixels constituting the polygon 50 are mapped by the conventional method based on this value. Find the value of. FIG. 2 is a schematic diagram showing a state in which the parameter (u, v) is mapped to the polygon 50. Lines such as meshes inside the polygon indicate vertical and horizontal lines on the parametric plane (ie, u = constant and v = constant).
[0012]
The mapping in the above-mentioned conventional method means that four vertices A (first vertex), vertex B (second vertex), vertex C (third vertex), vertex D (on the XY plane (display coordinate plane) It means an operation for obtaining point-by-point data on a pixel based on the coordinates of the fourth vertex) and various data (for example, texture coordinates, normal vector, hue, diffuse luminance, opacity, etc.). The calculation in the mapping means a series of calculations executed in the order of perspective transformation → interpolation along the contour → interpolation along the scanning line → reverse perspective transformation. The perspective transformation means that the data on each vertex of the data to be mapped is perspective transformed (conversion from the viewpoint coordinate system to the display coordinate system). The interpolation along the contour means an operation for changing the Y coordinate for each scanning line and obtaining data to be mapped to the X coordinate and the Z coordinate on the left and right contours. Interpolation along the scanning line means an operation for changing the X coordinate for each display pixel and obtaining data to be mapped to the Z coordinate on each pixel. Inverse perspective transformation means an operation for inversely transforming display coordinate system data on each pixel into a viewpoint coordinate system.
[0013]
Since the parametric variable (u, v) is mapped on each pixel, the following conversion equation T (u, v) = a + b · u + c · v + d · u · v (bilinear interpolation equation 1)
Can be used to determine the value of each mapping variable on each pixel.
Each of the coefficients a, b, c, d is
Value of mapping variable T (0,0) of vertex A (first vertex) = T0,
The value of the mapping variable T (0,1) of the vertex B (second vertex) = T1,
The value of the mapping variable T (1,1) of the vertex C (third vertex) = T2,
The value of the mapping variable T (1, 0) of the vertex D (fourth vertex) = T3,
When,
Coefficient a = T0,
Coefficient b = T3−T0,
Coefficient c = T1-T0 ,
Coefficient d = T0−T3−T1 + T2
It is.
FIG. 3 is a schematic diagram showing the principle of bilinear interpolation. From the value of the mapping variable on each vertex and the value of the parameter on each pixel, the value of the mapping variable on each pixel by the above bilinear interpolation formula 1. It can be obtained.
[0014]
As described above, the first embodiment has the following effects. Compared to the case where various mapping variables such as texture coordinates, normal vectors, hue, diffuse luminance, and opacity are mapped separately on each pixel constituting the polygon 50, a virtual representing all of them instead of the mapping variable. It is possible to simplify the hardware and software resources by mapping only the parameter that is the parameter of the parameter and performing the mapping by using the conversion formula from the parameter to the mapping variable.
[0015]
Embodiment 2. FIG.
Hereinafter, a second embodiment of the present invention will be described in detail with reference to the drawings. Mapping variables T (u, v) include texture coordinates (Tx, Ty), normal vector of polygon surface, hue, diffuse luminance, opacity, and the like. In the present embodiment, when the polygon 50 is triangular, in order to simplify the interpolation calculation, the vertex A (first vertex) and vertex B (of the triangular polygon 50 on the XY plane (display coordinate plane)) Second vertex), vertex C (third vertex), vertex A (first vertex) parameter (u, v) = (0, 0), vertex B (second vertex) parameter (U, v) = (0,1), parametric variable (u, v) = (1,0) of vertex C (third vertex) is normalized to an isosceles triangle, The parameters (u, v) are not limited, and the values at the vertex A (first vertex), the vertex B (second vertex), and the vertex C (third vertex) of the polygon 50 are represented by the uv plane ( When displayed on the parametric variable plane), the vertex A (first vertex), vertex B (second vertex), vertex C ( 3 vertices) the figure connecting with line segments only need to be pre-selected to be not zero state area or overlapped on a point Dari aligned on a straight line.
[0016]
Next, as in the case where the polygon 50 has a quadrangular shape (the first embodiment), mapping is performed by the conventional method to obtain the parametric variables (u, v) on all the pixels constituting the polygon 50. FIG. 4 is a schematic diagram showing a state where the parametric variable (u, v) is mapped to the polygon 50. Lines such as meshes inside the polygon indicate vertical and horizontal lines on the parametric plane (ie, u = constant and v = constant). Thereafter, a mapping variable T (u, v) to be mapped on each pixel constituting the polygon 50 is obtained from the parameter (u, v).
[0017]
That is, the following bilinear interpolation equation 2 is used as a conversion equation to perform an interpolation operation from the parameter (u, v) on all the pixels constituting the polygon 50 to the mapping variable T (u, v).
[0018]
T (u, v) = a + b · u + c · v (bilinear interpolation formula 2),
Each of the coefficients a, b, and c is the value of the mapping variable T (0, 0) of the vertex A (first vertex) = T0 and the mapping variable T (0, 1) of the vertex B (second vertex). ) Value = T1, and the value of the mapping variable T (1,0) of the vertex C (third vertex) = T2,
Coefficient a = T0,
Coefficient b = T2−T0,
Coefficient c = T1-T0,
And can be simplified as compared with the first embodiment.
FIG. 5 is a schematic diagram showing the principle of bilinear interpolation in the case of a triangle shape. The bilinear interpolation formula 2 is used to calculate the value of the mapping variable on each vertex and the value of the parameter on each pixel on each pixel. This indicates that the value of the mapping variable can be obtained.
[0019]
As described above, the second embodiment has the following effects. First, the first effect is that instead of mapping various mapping variables such as texture coordinates, normal vectors, hue, diffuse luminance, and opacity on each pixel constituting the polygon 50, the mapping variable is replaced with the mapping effect. It is possible to map only parametric variables, which are virtual parameters representing all of them, and execute mapping using transformation formulas from parametric variables to mapping variables, simplifying hardware and software resources. It can be done. The second effect is that when the polygon 50 has a square shape, the amount of calculation when mapping the texture coordinates on each pixel constituting the polygon 50, the normal vector of the polygon surface, the hue, the diffuse luminance, the opacity, and the like is performed. It can be reduced more.
[0020]
Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention. Further, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a suitable number, position, shape, and the like for carrying out the present invention. Moreover, in each figure, the same code | symbol is attached | subjected to the same component.
[0021]
【The invention's effect】
Since this invention is comprised as mentioned above, there exists an effect hung up below. Compared to the case where various mapping variables such as texture coordinates, normal vectors, hue, diffuse luminance, and opacity are mapped separately on each pixel constituting the polygon 50, a virtual representing all of them instead of the mapping variable. It is possible to simplify the hardware and software resources by mapping only the parameter that is the parameter of the parameter and performing the mapping by using the conversion formula from the parameter to the mapping variable.
[Brief description of the drawings]
FIG. 1 is a functional block diagram for explaining a drawing circuit according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing a state in which a parametric variable is mapped to a quadrangular polygon.
FIG. 3 is a schematic diagram showing the principle of bilinear interpolation in the case of a quadrangular shape.
FIG. 4 is a schematic diagram showing a state in which a parameter is mapped to a triangular polygon.
FIG. 5 is a schematic diagram illustrating the principle of bilinear interpolation in the case of a triangular shape.
[Explanation of symbols]
100 Drawing Circuit 110 Geometry Processor 120 Polygon Processor 121 Z Buffer 122 Paint RAM
130 Parametric mapping device 131 Texture memory 132 Attribute memory 140 Frame processor 150 Two-dimensional display processor 50 Polygon A, B, C, D Vertex ARGB Selected texture color data Fd Data identification flag Tx X direction component (horizontal direction component) of texture coordinate data )
Ty Y-direction component of texture coordinate data (vertical direction component)
DX Data of X direction component (horizontal direction component) of display coordinates u, v Parameter T Mapping variable

Claims (4)

In a mapping device that maps mapping variables onto each pixel,
Instead of various mapping variables, the parametric is a virtual parameter representative of the various mapping variables, and means for mapping for each pixel constituting the polygon,
Means for calculating a value on each vertex of the polygon of a mapping variable to be mapped onto the pixel among various mapping variables ;
Using the predetermined transformation formula determined based on the calculated value on each vertex, the value of the mapping variable on the pixel is calculated from the parameter mapped on the pixel, and mapping is performed. parametric mapping apparatus characterized by having a means for executing the. The polygon is a rectangle,
There are two variables in the parametric variable to form a parametric plane,
The values of the parametric variables (u, v) on the vertices are not in a zero area state where they are arranged on a straight line or overlapped on a point when displayed on the parametric variable plane. Are pre-selected so that they are not in a crossed twisted shape state,
The predetermined conversion equation for calculating the mapping variable T (u, v) is the following equation (1):
T (u, v) = a + b · u + c · v + d · u · v (1)
(However, a, b, c and d are constants)
The parametric mapping apparatus according to claim 1, wherein the parametric mapping apparatus is represented by: When the calculated values of the mapping variables of the vertexes of the polygon are T0, T1, T2, and T3, respectively, in the above equation (1), a = T0, b = T3-T0, c = T1-T0, and The parametric mapping apparatus according to claim 2, wherein a relationship of d = T0−T3−T1 + T2 is established. In a mapping method that maps a mapping variable onto each pixel,
Mapping device, instead of the various mappings variables, the parametric is a virtual parameter representative of the various mapping variables, a step of mapping for each pixel constituting the polygon,
The mapping device calculates a value on each vertex of the polygon of a mapping variable to be mapped onto the pixel among various mapping variables ;
The mapping device using a predetermined conversion formula determined based the calculated the value on each vertex, from the mapped the parametric on those 該Pi Kuseru, the Symbol mapping on the pixel parametric mapping method characterized by comprising the step of performing a mapping by calculating the value of the variable, the.

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