Comment on Nsio explains: Perspective by Nsio
Hi,
Regarding 2D perspective, if i wanted to draw a cube or rectangular prism at different perspectives, without zooming in or out, just moving the object up down left right (not rotate), HOW do the lengths, widths, and heights relate to each other? If based on a cube, is the width always greater than the length? Is there any relation to the foreshortening, as in if I moved the cube up or down, would the original height line decrease? And since we are able to see the top/bottom plane of the cube, would that have any relation to the height line decrease. Finally, am I complicating this stuff too much and should just rely on practice?
Regarding 2D perspective, if i wanted to draw a cube or rectangular prism at different perspectives, without zooming in or out, just moving the object up down left right (not rotate), HOW do the lengths, widths, and heights relate to each other? If based on a cube, is the width always greater than the length? Is there any relation to the foreshortening, as in if I moved the cube up or down, would the original height line decrease? And since we are able to see the top/bottom plane of the cube, would that have any relation to the height line decrease. Finally, am I complicating this stuff too much and should just rely on practice?
Unless you add new vanishing points to the right, left, up or down respectively, the object your are moving will become skewed.
The behavior you are looking for can be tested with two point perspective by drawing some cubes between the vanishing points in different places. Remember that if at any time you see one of the faces head on, there is a vanishing point in front of you (the sides are obviously receding to that point so you won't see them).
Now, if you start moving the cube to the right, the side from the left emerges, becoming wider the more you move to the right (while the front face width become narrower. When you are in the middle point between the vanishing points, the front and left face are equal in size and shape. If you keep moving, the procedure is the same, but "reversed". In other words, when you reach the vanishing point on the right, the face on the left will become the new front face. This exactly same thing happens with up and down, with respective faces becoming visible or hidden.
That said, the more you see one face of the cube, the less you will see other faces. That will also mean that the longer the edges are on the front face, the shorter they will be on the side faces, especially those edges that recede towards the vanishing point. So yes, if we see top/bottom face of the cube, it will have an effect on the foreshortening
To take in account the real behavior in perspective, if you keep moving an object in one direction, the farther away it will go from the beholder. That said, you won't be able to keep the object size the same unless you keep zooming in while you move it. If the beholder doesn't move, or the object doesn't orbit the beholder, the object will disappear once it reaches the other vanishing point because of the distance. In order to do this in 2D perspective, the guidelines need to curve so that the object won't become skewed.
You aren't complicating this, you are doing just the right thing by addressing the rules that you will need to understand in order to be successful in perspective. They are sort of complicated, yet so straightforward and simple. Once you understand the rules and you practice enough, you don't need to think in such complicated way because you will feel it.
The behavior you are looking for can be tested with two point perspective by drawing some cubes between the vanishing points in different places. Remember that if at any time you see one of the faces head on, there is a vanishing point in front of you (the sides are obviously receding to that point so you won't see them).
Now, if you start moving the cube to the right, the side from the left emerges, becoming wider the more you move to the right (while the front face width become narrower. When you are in the middle point between the vanishing points, the front and left face are equal in size and shape. If you keep moving, the procedure is the same, but "reversed". In other words, when you reach the vanishing point on the right, the face on the left will become the new front face. This exactly same thing happens with up and down, with respective faces becoming visible or hidden.
That said, the more you see one face of the cube, the less you will see other faces. That will also mean that the longer the edges are on the front face, the shorter they will be on the side faces, especially those edges that recede towards the vanishing point. So yes, if we see top/bottom face of the cube, it will have an effect on the foreshortening
To take in account the real behavior in perspective, if you keep moving an object in one direction, the farther away it will go from the beholder. That said, you won't be able to keep the object size the same unless you keep zooming in while you move it. If the beholder doesn't move, or the object doesn't orbit the beholder, the object will disappear once it reaches the other vanishing point because of the distance. In order to do this in 2D perspective, the guidelines need to curve so that the object won't become skewed.
You aren't complicating this, you are doing just the right thing by addressing the rules that you will need to understand in order to be successful in perspective. They are sort of complicated, yet so straightforward and simple. Once you understand the rules and you practice enough, you don't need to think in such complicated way because you will feel it.
Thank you for the quick reply.
So what you say makes a lot of sense, but is there an application or program I can use to try this out? I've been using sketch up but I noticed that in perspective mode, there is no foreshortening of the vertical lines when the eye line is above the cube. I also noticed that if I were to pan the camera to the extreme right or left, the bigger plane would never become one point perspective. So can you explain if this program is accurate?
Furthermore, when the cube is on the eye line and facing directly towards me, the width between the left and right vertical lines often exceeds the measurement of the cube's side length. So if I used 2 D perspective and drew the same cube throughout, I would be able to draw 1 main vertical line (which reduces in length as it strays from the middle of the eye line, right?) and 2 pairs of horizontal lines going towards the vanishing points that are set. How can I determine the width between the left and right vertical lines? Also, are the width between these lines constant if draw at different positions with the same vanishing points? (probably not if placing a cube on a vanishing point results in 1 point perspective, right?)
Also, I'm not sure if I understand what you mean by curved guidelines. Would they be like the fish eye example?
Thanks!!!
So what you say makes a lot of sense, but is there an application or program I can use to try this out? I've been using sketch up but I noticed that in perspective mode, there is no foreshortening of the vertical lines when the eye line is above the cube. I also noticed that if I were to pan the camera to the extreme right or left, the bigger plane would never become one point perspective. So can you explain if this program is accurate?
Furthermore, when the cube is on the eye line and facing directly towards me, the width between the left and right vertical lines often exceeds the measurement of the cube's side length. So if I used 2 D perspective and drew the same cube throughout, I would be able to draw 1 main vertical line (which reduces in length as it strays from the middle of the eye line, right?) and 2 pairs of horizontal lines going towards the vanishing points that are set. How can I determine the width between the left and right vertical lines? Also, are the width between these lines constant if draw at different positions with the same vanishing points? (probably not if placing a cube on a vanishing point results in 1 point perspective, right?)
Also, I'm not sure if I understand what you mean by curved guidelines. Would they be like the fish eye example?
Thanks!!!
The programs, sketchup included, are accurate. However, the phenomenon you are experiencing is due to the rules of perspective system. The vanishing points are infinitely far away, so if you were to pan the scene, you would need to pan infinitely far away and even then it wouldn't be the one point perspective you are looking for.
That's simply because that vanishing point won't be in front of you until you take a look at it or rotate the cube. When you do, the whole perspective view will change. There is a way to see this happening in sketchup. Simply make a cube and make some guidelines going along the edges. When you rotate the cube, the guidelines will rotate as well, indicating the placement of the vanishing point you are looking for. Here is an example I made some time ago: dl.dropboxusercontent.com/cont…
Besides, one point perspective is merely a simplification and works in certain scenes where the effects of the other vanishing points can be neglected. In reality there are vanishing point in every point you are looking at. However, we base our perception on our surroundings, like a room (I call this global perspective). Thus you will be basing your view on this room, which will have 6 vanishing points because there are 3 dimensions in 3D and each axis has one vanishing point at the end. You will only see as much as you can fit in your field of view though.
There can be only one vanishing point directly in front of you at any time. That's because the other 5 vanishing points are literally on the left, right, below, above and behind you. That said, you need to turn before you can see them, the same apply on sketchup and other programs as well. This will cause interesting things on 2D plane though. In order to show more vanishing points on a drawing, you need to rotate the eyes of the beholder towards the vanishing point in your drawing. This will cause a panorama view like here: www.fortlauderdaleobserver.com… . You know the road is straight, but it's still arcing in the image. This is what I mean with the curved perspective guidelines. In order to show vanishing points on the left and right and to make the guidelines recede towards the vanishing points, they just need to curve like that to emulate the missing third dimension. See more in this tutorial:
:origin()/pre00/ca62/th/pre/i/2015/299/5/c/nsio_explains__distortion_in_perspective_by_nsio-d9eh4to.png)
There are ways to determine the relative sizes of the edges/faces, but that involves constructing perspective which I'm not fond of. To me constructed perspective feels too rigid and limited, although it has its uses. I prefer curved perspective because that's how we would really see the scene in front of us. For me it's more important the cube "feels and looks like a cube" rather than it being mathematically correct. Anyway, here is an example how to construct perspective: www.automotiveillustrations.co…
That's simply because that vanishing point won't be in front of you until you take a look at it or rotate the cube. When you do, the whole perspective view will change. There is a way to see this happening in sketchup. Simply make a cube and make some guidelines going along the edges. When you rotate the cube, the guidelines will rotate as well, indicating the placement of the vanishing point you are looking for. Here is an example I made some time ago: dl.dropboxusercontent.com/cont…
Besides, one point perspective is merely a simplification and works in certain scenes where the effects of the other vanishing points can be neglected. In reality there are vanishing point in every point you are looking at. However, we base our perception on our surroundings, like a room (I call this global perspective). Thus you will be basing your view on this room, which will have 6 vanishing points because there are 3 dimensions in 3D and each axis has one vanishing point at the end. You will only see as much as you can fit in your field of view though.
There can be only one vanishing point directly in front of you at any time. That's because the other 5 vanishing points are literally on the left, right, below, above and behind you. That said, you need to turn before you can see them, the same apply on sketchup and other programs as well. This will cause interesting things on 2D plane though. In order to show more vanishing points on a drawing, you need to rotate the eyes of the beholder towards the vanishing point in your drawing. This will cause a panorama view like here: www.fortlauderdaleobserver.com… . You know the road is straight, but it's still arcing in the image. This is what I mean with the curved perspective guidelines. In order to show vanishing points on the left and right and to make the guidelines recede towards the vanishing points, they just need to curve like that to emulate the missing third dimension. See more in this tutorial:
There are ways to determine the relative sizes of the edges/faces, but that involves constructing perspective which I'm not fond of. To me constructed perspective feels too rigid and limited, although it has its uses. I prefer curved perspective because that's how we would really see the scene in front of us. For me it's more important the cube "feels and looks like a cube" rather than it being mathematically correct. Anyway, here is an example how to construct perspective: www.automotiveillustrations.co…
So can I try to summarize this all:
We see objects in 6 point perspective. Though would you apply them always to your drawings? And is 5 point perspective just one point perspective but with curved guide lines all around like in a sphere shape.
So how big is the field of view for drawing a regular scene. I don't want to draw panoramas but just what we see, but in this 5 point perspective picture s-media-cache-ak0.pinimg.com/o…, we wouldn't be able to actually see this much. So to conclude, we would only use the curved guidelines like that in the photo, but much smaller as in we won't be able to see the vanishing points.
And since the objects vanish left right up down and in front, any object that moves away from the center would mean that they would shrink in size (ignoring moving towards and away). But would you draw someone walking perpendicular to you shrinking as they walk further from you? That seems weird even though it makes sense to my eyes. However, when I watch anime, people don't shrink as they walk on a road with a still camera.
This is confusing. Hopefully, you can help me draw a cube in 9 different spots of a page with the same vanishing points without rotating or zooming. I really thought that this was the first step of drawing what we see.
Thank you!
We see objects in 6 point perspective. Though would you apply them always to your drawings? And is 5 point perspective just one point perspective but with curved guide lines all around like in a sphere shape.
So how big is the field of view for drawing a regular scene. I don't want to draw panoramas but just what we see, but in this 5 point perspective picture s-media-cache-ak0.pinimg.com/o…, we wouldn't be able to actually see this much. So to conclude, we would only use the curved guidelines like that in the photo, but much smaller as in we won't be able to see the vanishing points.
And since the objects vanish left right up down and in front, any object that moves away from the center would mean that they would shrink in size (ignoring moving towards and away). But would you draw someone walking perpendicular to you shrinking as they walk further from you? That seems weird even though it makes sense to my eyes. However, when I watch anime, people don't shrink as they walk on a road with a still camera.
This is confusing. Hopefully, you can help me draw a cube in 9 different spots of a page with the same vanishing points without rotating or zooming. I really thought that this was the first step of drawing what we see.
Thank you!
I always apply 6 point perspective in my drawings. However, the amount of distortion depends on the distance between the beholder and the object. It will determine how much the beholder needs to move her eyes to see the object/scene. The more movement required, the more distortion will take place.
Humans have field of vision of ~120 degrees, but you as the artist determine the focal and how much you want to fit within the canvas. Then it's up to you to decide whether you can deal with the limitations of constructed perspective or if you want to apply more real distortion. When the target isn't extremely close to the beholder, distortion can be neglected, making 1-3 point perspective a viable choice. If you want immersion, then small distortion will do the trick. And yeah, we normally can't see as much as shown in the 5-point perspective example.
In any event, if someone is walking away from you, be it a perpendicular or parallel path in relation to where you are looking at, that person will still move away from you and therefore shrink. It feels weird only because of the conversion between 3D and 2D. It just works that way and when you can accept that, perspective is relatively simple. However, you can't make any conclusions based on anime. First and foremost, anime is all about simplification. As long as the character appears to be walking, there may not be any need to take everything in account. The animators save a lot of effort by doing it that way and they sill achieve acceptable results.
No problem.
Humans have field of vision of ~120 degrees, but you as the artist determine the focal and how much you want to fit within the canvas. Then it's up to you to decide whether you can deal with the limitations of constructed perspective or if you want to apply more real distortion. When the target isn't extremely close to the beholder, distortion can be neglected, making 1-3 point perspective a viable choice. If you want immersion, then small distortion will do the trick. And yeah, we normally can't see as much as shown in the 5-point perspective example.
In any event, if someone is walking away from you, be it a perpendicular or parallel path in relation to where you are looking at, that person will still move away from you and therefore shrink. It feels weird only because of the conversion between 3D and 2D. It just works that way and when you can accept that, perspective is relatively simple. However, you can't make any conclusions based on anime. First and foremost, anime is all about simplification. As long as the character appears to be walking, there may not be any need to take everything in account. The animators save a lot of effort by doing it that way and they sill achieve acceptable results.
No problem.
So when you say move her eyes, do you mean turning the head. In the example of the distorted table, did you apply distortion because normally you would only be able to see a smaller portion of the table but when you turn your head (or eyes?) you are then able to see the left and right sides of the table, and thus that's why you applied distortion to a close object, right? And you wouldn't apply it to an object farther away because you wouldn't need to turn your head/eyes, right?
Anyways, I'm very grateful for your help.
Anyways, I'm very grateful for your help.
Yes, I mean just that. Constructed perspective doesn't take that eye movement in account, and that's its greatest strength and weakness. If there isn't movement and distortion, the lines will be straight and easy to construct with guidelines. Therefore 1,2 and 3 point perspective will work as long as you don't try drawing anything that would require eye movement, because they are beyond the limitations of the static perspective system.
Also, I think that if I were to just draw a cube in the center between the two vanishing points and drew a random vertical lines and two pairs of horizontal lines... Would those horizontal lines be the original height of the cube but at different positions (left or right of the center)? And if this is so, drawing a cube on the vanishing point would be invisible?
Or would the line from the other vanishing point create the new front face? Kinda like in this perspective grid although I don't really understand them ... www.thedrawingwebsite.com/wp-c…
What I mean is do the green lines at for example, the right vanishing point become the new face? And if so, I would have thought that the height of that vertical line would be shorter than the one in the center of the two vanishing points.
Also, would this be an accurate representation? on page 26 even though the cubes don't get smaller at the sides?www.thedesignsketchbook.com/wp…;
Thanks!
Or would the line from the other vanishing point create the new front face? Kinda like in this perspective grid although I don't really understand them ... www.thedrawingwebsite.com/wp-c…
What I mean is do the green lines at for example, the right vanishing point become the new face? And if so, I would have thought that the height of that vertical line would be shorter than the one in the center of the two vanishing points.
Also, would this be an accurate representation? on page 26 even though the cubes don't get smaller at the sides?www.thedesignsketchbook.com/wp…;
Thanks!