DCG Study Topics

Have a look at the examples below from our students. There's no one right note making style but whatever you do, things that help are:
  • Use colour to help make things clear
  • Summarise the steps involved - don't just copy the page from the textbook
  • Draw a diagram

Orthographic Projection of Curves

A basic skill that you need to know. 
  • 30 degree slices
  • Ordinates
  • Working with cones
  • Section planes

​Ellipse, Parabola & Hyperbola

Three different types of conic sections.
  • Circle method for ellipse
  • Rectangle method for parabola
  • Eccentricity method (including how to find V)
  • Eccentricity equation
  • Drawing a focal sphere
  • Finding F, V and DD using the focal sphere
  • ​Tangents to a curve

Intersection of Solids

Finding where two objects intersect.
  • How to draw plan & elevation of an inclined prism
  • Labelling points
  • Using an auxiliary view
  • Bend points on edges in auxiliary
  • Radial elements to find points
  • Hidden or not?
  • Projecting between plan & elevation

Auxiliary Views

These skills are used throughout the subject. 
  • What does a 1st auxiliary view show us?
  • Where do the heights come from?
  • When would you draw a 2nd auxiliary view?
  • How to you draw a 2nd auxiliary view?
  • Using a measuring line
  • Using auxiliary views to find a dihedral angle

Oblique Plane

A general skill that comes up in lots of different questions.  
  • Projecting from plan to elevation using VTH
  • Finding trace of a plane (make sure you're clear on this!)
  • Auxiliaries with VTH
  • True inclination
  • Solid cuts (using auxiliaries)
  • True shape of a surface cut
  • Finding the line of intersection on two intersecting oblique planes

Perspective

See pp 90-97, 100-102. To test your understanding try 2015 B-3.
  • Drawing picture plane - what angle
  • Finding vanishing points
  • Drawing ground line & horizon
  • Auxiliary vanishing points
  • Finding heights (2 methods)
  • Working around the drawing
  • Circles in perspective

Developments

See pp 193-196, 209-213
  • Prisms
  • Pyramids (radial method)
  • Curved surfaces
  • Oblique solids (auxiliaries or true lengths)

Geologic Geometry

Mining - see pp 353-356 & pp 362-363
  • Terminology: stratum, headwall, footwall, dip, strike, borehole, outcrop
  • Understanding contour lines
  • Drawing an elevation from a contour map
  • Finding strike, dip & thickness
  • How to draw a skew borehole
  • Using auxiliaries so solve problems
​
Earthworks - see 357-361 & 367-369
  • Terminology: formation, cuttings, embankments
  • Level roads including bends
  • Inclined roads (where do you draw the semicircle?)

Envelopments

See pp 201-205
  • What is an envelopment?
  • Prisms
  • Cylinders
  • Partial envelopments

Skew Lines

2 varieties, both quite similar. Very practicable. See pp168-170
  • Finding a 5th point, E
  • Using E in plan to find X1Y1
  • Determining direction of X2Y2
  • Finding shortest distance
  • Projecting back to plan and elevation

Axonometric Projection

See pp74-83
  • What is the difference between isometric, dimetric and trimetric?
  • Setting up axes  
  • Projecting to find the 3D view
  • Working backwards
  • Working with curves

Isometric Projection

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