<< Chapter < Page Chapter >> Page >
  • GM01.Point3D.draw
  • GM01.Vector3D.draw
  • GM01.Line3D.draw

The method named GM01.Point3D.draw

Recall that a point simply represents a location in space and has no width, height, or depth. Therefore a point is not visible to the human eye.However, it is sometimes useful to draw a small circle around a point to mark its location for human consumption. That is the purpose of the draw method of the GM01.Point3D class, which is shown in its entirety in Listing 4 .

Listing 4 . The method named GM01.Point3D.draw.
public void draw(Graphics2D g2D){//Get 2D projection coordinate values. ColMatrix2D temp = convert3Dto2D(point);drawOval(g2D,temp.getData(0)-3, temp.getData(1)+3,6, 6);}//end draw

Purpose of the method

This method draws a small circle around the location of a point in 3D space. The 3D location of the circle is projected onto the 2D plane of the specifiedgraphics context for display later on a 2D screen. The code in Listing 4 projects that location in 3D space onto the 2D plane by calling the staticmethod named convert3Dto2D .

Behavior of the GM01.Point3D.draw method

The location of a point in 3D space, as represented by an object of the GM01.Point3D class, is actually stored in an object of the GM01.ColMatrix3D class. A reference to that ColMatrix3D object is stored in the instance variable named point belonging to the Point3D object. This reference is passed as a parameter to the convert3Dto2D method in Listing 4 .

Recall from Listing 1 that the convert3Dto2D method receives an incoming reference to an object of the class GM01.ColMatrix3D and returns a reference to an object of the class GM01.ColMatrix2D , which contains the horizontal and vertical components of the projection of the 3D point onto a2D plane.

Using the returned GM01.ColMatrix2D object

Listing 4 uses the horizontal and vertical components stored in the returned ColMatrix2D object to construct the proper parameters and call the wrapper method named GM01.drawOval . This wrapper method doesn't know that it is receiving parameters that were originally derived from an objectin 3D space. The world of the wrapper method is confined to 2D space. The wrapper method named GM01.drawOval performs the following actions:

  • casts the four incoming numeric parameters to type int ,
  • flips the sign on the vertical component to resolve the issue regarding the positive value for the y-axis, and
  • passes the parameters to the drawOval method of the standard Graphics class to cause a small circle to be drawn at the correct location on the 2D off-screen image.

The small circle is not converted to an ellipse

Note that even though the location of the point in 3D space is projected onto the 2D plane, the shape of the small circle is not converted to an ellipse toreflect the 3D to 2D conversion nature of the operation. Thus, if the circle were large, it wouldn't necessarily look right. However, in thiscase, the only purpose of the circle is to mark the location of a point in 3D space. Therefore, I didn't consider the actual shape of the marker to betoo important. Figure 1 shows examples of circles marking points in 3D space at the corners of the box and at the ends of the axes.

Questions & Answers

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Game 2302 - mathematical applications for game development. OpenStax CNX. Jan 09, 2016 Download for free at https://legacy.cnx.org/content/col11450/1.33
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Game 2302 - mathematical applications for game development' conversation and receive update notifications?