ISO 14306:2017 産業オートメーションシステムと統合—3D視覚化のためのJTファイル形式仕様 | ページ 6

3.1.1

3D visualization

visual presentation on a screen or another media of graphical and textual three dimensional representations of a set of data representing an object, information or results of a computational process in order to facilitate capture of the understanding of the object, for visual information sharing with users and sometimes to promote decision process by a human looking at the data visualized in a medium

3.1.2

assembly

related collection of model parts, represented in a ISO 14306 format logical scene graph as a logical graph branch

3.1.3

attribute

objects associated with nodes in a logical scene graph and specifying one of several appearances, positioning, or rendering characteristics of a shape

3.1.4

code text

collection of data in encoded form

3.1.5

coordinate system

system which uses one or more numbers, or coordinates, to uniquely determine the position of a point or other geometric element

Note 1 to entry: If not otherwise specified in a data field’s description, it is assumed that the data is defined in Local Coordinate System.

3.1.6

degenerated surface

place where a region of the parameter space of the surface is mapped to a single point of Cartesian space

Note 1 to entry: This means that there are several (u,v) parameters defining the same 3D point of the surface. In this region, one or both first partial derivatives are zero. The tip of a cone or the poles of a sphere are common examples.

3.1.7

directed acyclic graph

graph that consists of a set of nodes and a set of edges that connect the nodes in a tree like structure

Note 1 to entry: A directed graph is one in which every edge has a direction such that edge (u,v), connecting node-u with node-v, is different from edge (v,u).

Note 2 to entry: A directed acyclic graph is a directed graph with no cycles ここで, a cycle is a path (sequence of edges) from a node to itself.

Note 3 to entry: With a directed acyclic graph, there is no path that can be followed within the graph such that the first node in the path is the same as the last node in the path.

3.1.8

JT enabled application

application which supports reading and/or writing reference compliant ISO 14306 format files

3.1.9

level of detail

LOD

alternative graphical representation for some model component such as part

3.1.10

local coordinate system

LCS

coordinate system that is used to specify the raw data of the shape geometry with no transforms applied

3.1.11

logical scene graph

LSG

scene graph representing the logical organization of a model

Note 1 to entry: A scene graph contains shapes and attributes representing the model’s physical components, properties identifying arbitrary metadata (e.g. names, semantic roles) of those components, and a hierarchical structure expressing the component relationships.

3.1.12

mipmap

reduced resolution version of a texture map

Note 1 to entry: Mipmaps are used to texture a geometric primitive whose screen resolution differs from the resolution of the source texture map originally applied to the primitive.

3.1.13

model

representation, in ISO 14306 format, of a physical or virtual product, part, assembly; or collections of such objects

3.1.14

model coordinate system

MCS

local coordinates transformed by any transforms specified as attributes at or above the node

3.1.15

product and manufacturing information

PMI

collection of information created on a 3D/2D CAD model to completely document the product with respect to design, manufacturing, inspection, etc.

3.1.16

property

object associated with a logical scene graph node and identifying arbitrary application or enterprise specific information (meta-data) related to that node

3.1.17

quantize

constrain something to a discrete set of values, such as an integer or integral multiplier of a common factor, rather than a continuous set of values, such as a real number

3.1.18

scene graph

directed acyclic graph that arranges the logical and often (but not necessarily) spatial representation of a graphical scene

3.1.19

shader

user-definable program, expressed directly in a target assembly language or in high-level form to be compiled, that calculates colour values at a pixel based upon data such as lighting, surface colour and texture

Note 1 to entry: A shader program replaces a portion of the otherwise fixed-functionality graphics pipeline with some user-defined function.

Note 2 to entry: At present, hardware manufacturers have made it possible to run a shader for each vertex that is processed or each pixel that is rendered.

3.1.20

streaming

loading from disk based medium only the portions of data that are required by the user to perform the tasks at hand

Note 1 to entry: The motivation for sreaming is to more efficiently manage system memory.

Note 2 to entry: Transfer of data in a stream of packets, over the internet on an on-demand basis ここで, the data is interpreted in real-time by the application as the data packets arrive.

Note 3 to entry: The motivation for streaming is that the user can begin using or interacting with the data almost immediately - no waiting for the entire data file(s) to be transferred before beginning.

Note 4 to entry: The desired end result of streaming is to deliver only the ISO 14306 data that the user needs ここで, the user needs it, when the user needs it.

3.1.21

shape

logical scene graph leaf node containing or referencing the geometric shape definition data (such as vertices, polygons and normals) of a model component

3.1.22

texture channel

texture unit plus the texture environment

Note 1 to entry: The ISO 14306 format meaning for texture channel is the same as in OpenGL [1].

3.1.23

texture object

named cache that stores texture data, such as the image array, associated mipmaps, and associated texture parameter values: width, height, border width, internal format, resolution of components, minification and magnification filters, wrapping modes, border colour, and texture priority

Note 1 to entry: The ISO 14306 format meaning for texture object is the same as in OpenGL [1].

3.1.24

texture unit

piece of hardware that takes a sample of a texture

Note 1 to entry: The ISO 14306 format meaning for texture unit is the same as in OpenGL [1].

3.1.25

view coordinate system

world coordinates transformed by a view matrix

3.1.26

world coordinate system

WCS

node coordinates transformed by transforms inherited from a node’s parent (i.e. the coordinate system at the root of the graph)