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 Week
Four Lecture: Oblique Drawings/Mid-Term Exam
 Return
to Classroom
It is a necessity
that you read and follow all instructions throughout the Lecture.
Lectures are designed with interactivity, to aid in the learning
process. Often times the lectures will include tips for properly
completing assignments. Be sure to read all information, view all
Audio and Video files and complete all practicals associated with
each lecture.
Overview
Plan Oblique
Elevation
Oblique
Recap
 Overview
Well this is
a big week for us. We have reached the halfway point in the course
and are now experts at lettering and linework. This week we will
begin to draw three-dimensional drawings and we will be taking the
Midterm Exam. The Midterm needs
to be taken in a proctored
environment. See class "Schedule" for Exam due dates.
The oblique
drawings that we are going to master this week are paraline drawings.
In paraline drawings parallel lines remain parallel to each other.
In perspective drawings the parallel lines converge to the vanishing
point. Paraline drawings are used to quickly construct a three-dimensional
drawing. Paraline draws can be easily developed from plans and elevations.
The two types
of oblique drawings we are going to study are the plan oblique
and the elevation oblique.
In the plan
oblique drawing, the plan or top view of the building may
be used as the base drawing. In the plan oblique drawing the true
size and shape of the building is maintained and can be scaled.
In these drawings the plan is rotated usually at 30, 45 or 60
degrees. We will use 45 degrees for all of our oblique drawings.
In the elevation
oblique drawing, the elevation may be used as the basse drawing.
Here, the building elevations maintain their true size and shape.
In elevation oblique drawings the elevation is not rotated. Instead
the lines for the side and the top of the building are drawn as
receding lines at 30, 45 or 60 degrees. We will use 45 degrees
for all of our receding lines.
As we proceed
through the following exercises you will also begin to develop you
visualization skills. At first, you may not know exactly what you
are looking at. The more drawings you do the more your eyes will
adjust to these kinds of drawings. So think of this as visual training
as well as learning to draw.
Plan
Oblique
The following
activity will lead you through the construction of a plan oblique
drawing. You will follow the directions and in the end produce a
3D drawing. The subject of this exercise will be a 3' cube.
Assignment
4A Tips:
Begin by getting your paper set up. You'll need your scale, 45
degree triangle, T-square and of course your lead holder. All
of the lines will be drawn as light guidelines.
Draw the top
view of the 3' cube at 1" scale. Measure and draw the 3'
line at the top first. Then draw an X as shown. Next, draw the
two side lines and finally the bottom line. Remember - measure
once. Now darken the lines of the square in.
Click
here to view a sample drawing
Now that the
top view (plan) is drawn we want to use it to construct our oblique
drawing. For a plan oblique drawing we rotate the plan and for
this exercise we will rotate it 45 degrees. Use your 45-degree
triangle to make sure the rotation angle is correct.
Click
here to view a sample drawing
Now that the
plan is rotated we can use this as the bottom of the cube. From
the bottom we need to begin to project the sides of the cube up.
To do this draw a line straight up from each corner.
Click
here to view a sample drawing
Now we need
to find the top edge of the cube. To do this measure up 3' along
one of the lines we just drew. Now, using your 45-degree triangle,
project that point to each of the other lines. Draw a 45-degree
line between each vertical line.
Click
here to view a sample drawing
You should
now have an oblique drawing of the 3-foot cube. It is transparent
at the moment - you can see through it. In order to make it solid
you need to put another sheet of vellum on top of your drawing
and trace the lines you would see if you were looking from above
at a solid cube. Use light lines to draw the solid cube on your
own and then check the solution.
Click
here to view a sample drawing
Now that we
have the solid cube lets finish this drawing up. The finished
plan oblique drawing of the cube should have a 1 foot grid on
it and the correct line weights. Here are the steps for finishing
the cube drawing.
GRID: Use
your scale to mark 1'-0" tick marks on the base of the cube.
Remember what scale you are using. Draw the grid lines up the
sides of the cube. Now you have the vertical grid lines. Next
we need to get the horizontal grid lines. Mark 1'-0" tick
marks up the front edge of the cube and draw in your grid lines.
The final step is to project the grid across the top of the cube.
LINE WEIGHT:
Until now whenever we have talked about line weights we have used
the line weight rules for 2D drawings. Now that we are working
on a 3D drawing we need to think about line weight differently.
We are no longer concerned with what is closest to us. Now we
are concerned with the edges of the object. We are looking for
which edges are strongest.
(Insert
finished cube w/grid no line weight.)
As we think
about the line weight for the cube we must think about its surface
and the edges. Review the rules for using line weight in 3D drawings.
Click
here to view a sample drawing
(Line
weight link)
Have
Questions?
If
you have questions regarding any of the material covered in this
section, visit the "Week Four: Plan Oblique" Discussion
Forum. The forum can be accessed by clicking on the "Activate
Course WebCT Account" link located on the course "Classroom"
page. Once inside WebCT's discussion board, post questions and/or
comments under the appropriate forum.
Elevation
Oblique
The following
activity will lead you through the construction of an elevation
oblique drawing. You will follow the directions and in the end produce
another amazing drawing. This drawing of the 3' cube will emphasize
the elevation of the cube, hence it's name - elevation oblique.
Assignment
4B Tips:
Begin by getting your paper set up. You'll need your scale, 45
degree triangle, T-square and of course your lead holder. All
of the lines will be drawn as light guidelines.
Draw the elevation
of the 3' cube at 1" scale. Measure and draw the ground line
first.
Click
here to view a sample drawing
Now that the
front elevation is drawn, we want to use it to construct our elevation
oblique drawing. For the elevation oblique drawing we use the
elevation just as you drew it. Tape it down to your drawing surface
and place a piece of vellum on top of it. Trace the front elevation
but do not show the ground line. 3D drawings do not show ground
lines.
In elevation
oblique drawings the sides of the object are projected back at
a 45 degree angle.
Click
here to view a sample drawing
We need to
find the back edge of the cube. To do this we use our scale and
measure along that line and mark the 3'-0" point. Do this
on only one of the parallel lines. Now draw a line up and over
to complete the cube.
Click
here to view a sample drawing
You should
now have an elevation oblique drawing of the 3-foot cube. It is
transparent at the moment . In order to make it solid you need
to put another sheet of vellum on top of your drawing and trace
the lines you would see if you were looking from the front at
a solid cube. Use light lines to draw the solid cube on your own
and then check the solution.
Click
here to view a sample drawing
You probably
notice that the elevation oblique drawing doesn't look much like
a cube anymore. It looks too deep. You may think you did something
wrong but you didn't. If it looks like the solution above you
did draw it correctly. The problem with Elevation Oblique drawings
is that they look distorted. Look back in the Ching book for more
information, page xxx (insert page number).
Let's finish
this drawing up. The finished elevation oblique drawing of the
cube should have a 1 foot grid on it and the correct line weights.
Do this the same way you finished the Plan Oblique drawing. If
you need to review the grid and line weight information for that
drawing. The finished drawing should look like this:
Click
here to view a sample drawing
Have
Questions?
If
you have questions regarding any of the material covered in this
section, visit the "Week Four: Elevation Oblique"
Discussion Forum. The forum can be accessed by clicking on
the "Activate Course WebCT Account" link located on
the course "Classroom" page. Once inside WebCT's discussion
board, post questions and/or comments under the appropriate forum.
Recap
Hopefully, everyone
is amazed by their ability to draw three-dimensionally. We covered
a lot in this week's class plus the midterm exam.
Next week we
will continue working with oblique drawings. We will review the
process for plan oblique and elevation oblique drawings. We will
use the plan oblique drawing of the cube in our exercise for next
week—don't get rid of last week's drawings.
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