One Point Perspective
In a one point perspective drawing everything seems to diminish as the objects recede into the distance and eventually disappear or vanish at a point in front of you.
As we look into one point perspective there some key terms to know; horizon line, vanishing point, and orthogonal lines.
In exterior scenes or other scenes where the outside is shown the horizon line is often where the sky meets the ground. Be careful as the horizon, or the point where the sky meets the ground is not always visible so its best to think of the horizon line as being at the viewers eye level.
, are the lines that move from the object to the vanishing point. The purpose of these lines is to set up the visual path to the vanishing point, directing the shape of the object in perspective.
When drawing a cube the edges of the cube will be perpendicular to the horizon line and the top and bottom of the cube will be parallel to the horizon line.
Remember that the orthogonal line is a guide it is not the actual edge of the object. The edges of more organic shapes will not trace along the orthogonal lines. Instead you will use those lines as a guide from the leading edge back to find how the object fits into perspective and create the shape to create the sense of space.
There is much more to one point perspective, but this will give you a starting point to work from. Just keep in mind that everything will diminish in size as the objects recede in the scene and the all diminish along a path back to a single point and you will be able to work out one point perspective.