Perspective and Vanishing Points
(note: to find your line of sight, pretend there is a laser beam shooting straight out from a point between your eyes)
When looking at a scene, be it a room or countryside with buildings etc,how do I determine the number of vanishing points that are required?Answer:
Firstly, both the interior of a room and the outside walls of a building are usually made up of a series of parallel and perpendicular lines (like boxes). If your line of sight is perpendicular to one of those walls then you use one point - and if your line of sight hits any of those walls at an angle (not a right angle) you use two points - but read on for more clarification...One Point Perspective -
Pretend you are standing in the middle of a 4 walled room, looking straight ahead at one wall. The wall to the right and left of you will be parallel to each other, and both will be perpendicular to the walls behind and in front of you. The rule of perspective is that parallel lines moving away from you in space all converge at the same vanishing point. Therefore, in the above scenario the wall right in front of you is not moving away from you (it is static) - but the walls to your left & right are getting further from you as they reach the wall you are staring at - you would draw the lines on those walls so that they all come out of one vanishing point.Two Point Perspective -
Now pretend you turn your body so that you are staring at a corner of a room. Both the wall to your left and to your right are moving away from you in space and only the corner is static, therefore you would use 2 point perspective...Outdoors -
The above rules also apply to exterior walls.Three Point Perspective
- Pretend you are standing at the corner of a city block, looking up at a skyscraper. Not only are
the side walls of the building moving away from you, but all of the the vertical lines of the building will also be moving away from you (up into the sky), so you'd add a third vanishing point way up above the building.Multiple Buildings -
If you are drawing several buildings they will share vanishing points ONLY if they stand at right angles to one another (such as in a grid). However, if you have two buildings which are not parallel or perpendicular to one another, EACH building will have it's own set of vanishing points ... (this is where things can get complicated).Question 2
When using more than 1 vanishing points (2,3,4, vanishing points etc) how do I think clearly to resolve lines to the correct vanishing points and prevent myself from resolving to the wrong vanishing points?Answer:
Ok, so lets pretend you are still staring at the corner of the room - the wall to your right is moving away from you in what direction? just lift up right your arm and follow the line of the ceiling - closest to furthest point - your arm will begin at your side and move towards the left -- the opposite is true for the left hand wall (lift up your left arm, follow the line of the ceiling right next to you, and notice that your arm moves towards the right as that line moves away from you in space) ... Simply put, wall lines to the left of the corner will meet at a vanishing point on the right hand side of your drawing, and walls to the right of the corner will converge at a point on the left hand side of your drawing --- HOWEVER, if your room has more than 4 walls (or has corners that come forward into space), the vanishing point will alternate at every new corner! if this seems confusing, just remember that all walls which are parallel to each other will converge at the same vanishing point...
I hope this helps a bit!