Illustrate the back face detection method, Data Structure & Algorithms

Assignment Help:

Illustrate the Back Face Detection Method

A single polyhedron is a convex solid, which has no external angle between faces less  than 180° and there is a simple object space method to determine which faces are the  visible front faces, and which are the hidden back faces.

The faces are characterized by their outward normals, and for this reason, the method is  also known as the Outward Normal Method.  The outward normal for every face of the convex solid is determined by taking the  cross-product of any two adjacent sides of the face. For consistency in checking, when  the viewer looks directly at the face under consideration, the vertex numbering (naming)  scheme for all faces must be in the same direction, say counter-clockwise. We need to start with a single polygon numbered in the proper order. There are analytical methods for doing this, but where user has control over the input, it is much easier to number the first polygon counter-clockwise when visible to the viewer.

Once this is done, any adjacent polygon will have the common edge traversed in the opposite direction, and hence no further decision-making will be necessary regarding the direction of numbering. This logic is particularly helpful in naming the faces away from the observer and those that are approximately horizontal, eliminating the need for the observer to imagine himself at all sorts of odd viewing angles.

 


Related Discussions:- Illustrate the back face detection method

Flowcharts, draw a flowchart which prints all the even numbers between 1-50...

draw a flowchart which prints all the even numbers between 1-50

Program of insertion of an element in list, Program will demonstrate the in...

Program will demonstrate the insertion of an element at desired position /* Inserting an element into contiguous list (Linear Array) at particular position */ /* contiguous_

Binary search tree, A binary search tree (BST), which may sometimes also be...

A binary search tree (BST), which may sometimes also be named a sorted or ordered binary tree, is an edge based binary tree data structure which has the following functionalities:

Illustrate the visual realism applications, Illustrate the Visual realism a...

Illustrate the Visual realism applications a)   Robot Simulations : Visualization of movement of their links and joints  and end effector movement etc. b)  CNC programs ver

Representation of arrays?, A representation of an array structure is a mapp...

A representation of an array structure is a mapping of the (abstract) array with elements of type T onto the store which is an array with elements of type BYTE. The array could be

Recurrence relation, solve the following relation by recursive method: T(n...

solve the following relation by recursive method: T(n)=2T(n^1/2)+log n

Tree traversals, There are three kinds of tree traversals, namely, Postorde...

There are three kinds of tree traversals, namely, Postorder , Preorder and Inorder. Preorder traversal: Each of nodes is visited before its children are visited; first the roo

Applications of the queue, Write down any four applications of the queues. ...

Write down any four applications of the queues.                                                            Ans. A pp li cation of Queue is given below (i)  Queue is

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd