2D Entities Ellipses Arcs and Curves Video Lecture - TurboCAD A Complete

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in this video we will go over how to
draw ellipses arcs and curves let's
start out by
clicking the blank space in the turbo
CAD workspace to bring up the customized
dialogue with the workspace dialog open
check the circle ellipse toolbar the arc
toolbar in the curve toolbar let's get
right to it and start with the ellipse
tools which are located on the right
side of the circle ellipse tool bar the
standard ellipse tool places two points
along the circumference of the ellipse
as if you were marking the corners of a
circumscribed rectangle the rotated
ellipse requires four mouse clicks once
to mark the center the next to create
the angle and then the major radius
followed by the minor like most other
tools this geometry can be constructed
by entering specific values into the
inspector bar let's try it with the
rotated ellipse tool active first click
somewhere in the drawing area to mark
the center now tab into the inspector
bar input a major radius of 3 an angle
of 30 and a minor radius of 1 then
finish the operation by hitting enter on
your keyboard the fixed ratio ellipse is
constructed with two mouse clicks one
defining the center then a second click
along the circumference the major and
minor radii are set by a fixed ratio
defined by a numeric value for example a
ratio of two would mean that the major
radius is twice that of the minor for
each of the ellipse tools there is a
similar tool that creates elliptical
arcs these can be found on the right
side of the arcs toolbar just like the
ellipse tool the elliptical arc tool
starts by defining the corners of the
extents of the ellipse then defining the
start and end angle moving
counterclockwise to create the arc same
with the
in fixed ratio elliptical arcs and if we
take a look at the first three tools on
the left side of the arc toolbar you'll
notice that they are similar to the
first three tools in the circle toolbar
that we went over in a previous video
with the additional step of defining the
start and end goal to construct the arc
so far all the arc tools we have taken a
look at create an arc based on an
ellipse or circle arcs can also be
created by defining three points along
the circumference notice the one two
three and one three two on the icons of
these tools this is their order of
operations for both tools you first
enter the start point after that they
differ slightly for the one two three
arc the second defines the radius and
the third click defines the end point in
for the one three two you create the end
point before the radius the remaining
arc tools deal with different tangency
z' again these are very similar to the
tangent circle tools we went over in the
previous video I will go over each of
these tools starting with a tangent to
line arc tangent two line creates an arc
by first picking a line that will be
tangent to this arc after defining the
radius you then place what now looks
like a circle along the line you have
picked once this circle has been placed
the start and end point is input with
the end point being counterclockwise
from the start point our tangent to our
curve behaves the same but in this case
the arc will be drawn tangent to an
existing curve arc tangent to three arcs
constructs a circle by choosing an
inside or outside tangency of three arcs
and once the circle has been constructed
the start and end point can then be
chosen to construct the arc our tangent
to entities works the same but in this
case line segments can be selected as
well as curves when constructing the
circle before the start and end point of
the arc our input now arced
engine - two entities works a little
different you start the operation by
selecting two entities you would like
the arc to be tangent to a third click
defines the radius then a fourth click
chooses the side of the circle as if it
were trimmed at the intersections of the
tangent entities now let's take a look
at the curve toolbar the first three
tools spline by control points spline by
fit points and Bezier curve all create
continuous curves defined by control
points or knots you will hear me mention
both knots and nodes knots refer to the
point along the curve which controls the
curvature and nodes refer to the UI
element that controls them let's try
drawing a spline by control points
choose spine by control points from the
curve toolbar but before we draw
anything else let's open the properties
dialog and under curve check show frame
now go ahead and draw a spline by
clicking in the drawing area notice that
in addition to the curve there is a poly
line connecting the endpoints this is
helpful in seeing how your data input
affects the construction of the curve
after placing several control points
double click or hit the finish flag to
complete the operation now choose the
edit tool from the left side toolbar or
pop-up and select the spline you will
notice several blue nodes appear at the
control points try grabbing the
different nodes and moving them around
paying close attention to how this
affects the construction of the curve
multiple nodes can be selected by
drawing a fence around the nodes you
would like to select now let's switch to
a fit point spline by right-clicking and
choosing edit fit points from the local
menu notice how the nodes now appear
along the spline at the same points as
the knots now right-click and choose
properties from the local menu then turn
off show frame under curve properties so
we can see what's going on notice the
green handles near each end point of the
spline this helps control the curvature
of the knots near either end of the
spline you can place additional knots by
right-clicking along the curve and
choosing add knot nodes can also be
deleted try selecting a node
then deleting it by choosing delete
nodes in the local menu or inspector bar
deleting the node removes the knot and
affects the curvature set by the
remaining knots along the curve now
let's take a look at Bezier curves we
can best illustrate how the knots affect
the curvature by drawing a wave-like
pattern with tied oscillations
notice how the curve passes through the
midpoint of each segment of the frame
this is because each knot is set to have
equal curvature and until change that
curvature will be the same between each
knot if we select the curve with the
edit tool we will notice the blue nodes
representing the knots and the green
handles which control the curvature I
can turn off the frame so we can better
see what's going on here
notice that when I grab the green
handles they are adjusted evenly on both
sides again this is because the knots
are set to have equal curvature if we
look down to the inspector bar we will
see there are three different types of
control points equal curvature at Point
non equal curvature at Point and non
smooth at Point with non equal chosen
grabbing the different handles will
change the curvature of that side only
while the angle of the other side has
changed to keep the curve smooth
if non smooth is chosen then both the
angle of the curve and the curvature can
be changed with one side not affecting
the other all three control methods can
be used to edit the same curve and
although there is no specific setting
for each individual not switching
control methods will not affect not
unless its handles are adjusted in this
will conclude our video presentation for
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