Models Flashcards
(14 cards)
In computer graphics, objects are described as an approximation using…
Polygons
An approximation of an object’s surface using connected polygons is called…
A mesh
In order to render an object, it is critical that we define…
Surface normals
Surface normals are vectors that lie […] to the surface.
Perpendicular
A polygonal mesh must satisfy the following three criteria…
The intersection of two faces is either empty, a vertex or an edge.
Every edge must be shared by exactly two faces.
Faces must have normals facing in a consistent direction.
If, in a mesh, every edge is shared by exactly two faces, this is called…
A manifold mesh
Surfaces can also be approximated using polygonal meshes, using a technique called…
Mesh subdivision
Meshes typically have more polygons in high […] areas.
Curvature
GL_TRIANGLES, _FAN and _STRIP are three OpenGL methods used to help build meshes. What are the differences between them?
GL_TRIANGLES lets you build each vertex individually.
_FAN treats the first vertex as an ‘origin point’, then fills in the gaps.
_STRIP treats the model as one strip of vertices, which are then filled in with edges.
Sending an entire array of vertices to the GPU is inefficient. To fix this problem, we can have one array consisting of all vertices, and another array…
Consisting of triangles with indices that link directly to this vertex list
The three attributes for each vertex are…
Coordinates, colour and vertex normal
Two properties of light and materials are…
Colour, reflectivity, light source, transparency
To render a solid object, the faces of the model are rendered from the […] properties.
Vertices, lighting and material
Polygonal meshes are defined by their…
Vertices and properties
