Can someone help me on perspective for a cylinder object ?

3yr

Charline B.R.

I'm trying to exercise on perspective, a topic I avoided for years and I have trouble with how to calculate cylinder with a perfect round basis in a 2 points perspective.
The left tower in the back seems completly off. I tried multiple calculation but every time it's weird.
How do you calculate a perfect square on a 2 points perspective (which is what I tried to make my cylinder) ? The method I found looked correct but the result isn't convincing at all...
Any help or link would be appreciated :)

Hi! I'd be happy to help but can you tell me or show me approximately where you think your vanishing points are (the two on the sides and the central one, if you know it)? This will give me a better idea of the effect you're looking for.

To be able to construct a perfect square in perspective, you need to understand a little more perspective, so you can construct the vanishing points for the diagonals of the square. using a 'stationary point'. It goes too far to explain it here, but google is your friend. Let me know if you need help, and I will see if I can find some pointers.

Tear down the building at Right; Copy the tover-shape at right and place similar to the left towers place. Even if the buildings UNDER the towers are oval it will not effect the cylindrical shapes. Tower to the left might be slighlty smaller-- very litttle compared to the right tower as it in fact is a small bit away from your ount point , There shoulld be a perspective point far away to the left somewhere on the eye-point line. Pleace take no offence for me interfeering..

Hey Charline B.R. what a really nice drawing so far. The first thing i notice is that it seems to me like a one point perspective and not a two point perspective. All lines are pointing to one point (behind the right tower). Or is the other point really far to the left?
What i see on your left tower is that the top of the cone is not in the center of the base of the tower. A vertical line need to run from the center of tower cilinder and the cone tip and bottom circle need to lay on that center line. I found a youtube video showing the principle: https://youtu.be/zkIYARAJVIA
The roof of the tower is constructed of 2 cones that are overlapping, but both cones have their center on the vertical centerline. I hope my description is helping you in the right direction.

So I did a quick drawover of the scene in photoshop. A couple things I think you should note.
First is the concept of drawing through. The ellipse on the bottom is the tower looks quite off, and that is because you are not drawing the entire shape, just the front of it, as a result, the ellipse comes off quite flat. Another thing to remember is that ellipse(and flat planes aswell, will get fatter the further they get from the horizon line. I did a quick chart on the side to illustrate what I mean.
Second is to block out the shapes. Start with a basic cube, and then draw an ellipse inside. When you have it blocked out, it follows the correct perspective. Your tower sort of melts away because it lacks the correct structure that the rest of your buildings have.
Finally try and find the centerpoint of shape. The best way is to do an x from the corners of the bottom plane(in a cube) and the center of that x is the middle. There you can draw a straight vertical line and find the point of your cone.
If you have any questions or need me to clarify, feel free to ask.
The drawing is looking really good by the way. Looking forward to seeing the finished piece :)

Hey, that's a very pretty scene. :)
I think the problem is conceptual rather than technical; it might be that the perspective of the tower's roof doesn't agree with the perspective of the rest of the composition.
It seems to me that the cone of the tower is angled in such a way that I'm seeing a lot more of the underside than I would be able to from the viewer's vantage point as you've defined it. Possibly adjusting the cone's angle so that less of the underside is showing might solve the problem?

short answer- the way you drew the red lines is "correct". I don't understand why you slanted the coned roof- and the longer answer involves understanding the limitations of linear perspective (which- gasp! isn't perfect). can you show the construction lines you used and why you angled the roof?