Tilt boxes in a correct perspective grid

[lvlingArtist]

Red circle shows the lamp I am trying to create in a correct perspective grid.

Blue circle is how I eyeballed it. Not correct at all, I just drew it.

Orange circle I tried to rotate the box, but the result is not the perspective I wanted like the eyeballed version.

How do I make the box around the upper lamp so that it is in the position of my eyeballed version?
How and where do the flight points go?

[darktiste]

First make straight line you got crocked line and it not even 3 point perspective... you can't get good structure if you can't draw a straight line.

Also an other thing is you put the perspective point away from each other if they are to close to the subject this create distortion just be aware of that

I think you should slow down. For example get back to this point and start to divide the cube like shown in the next video i will link down below not this one---) https://www.youtube.com/watch?v=1ugxyPd7cH0 this one is what you should be doing currently don't shot a bear before you know how to shot.

But your main problem is that this shape is ouside of your main cube which mean you have no unit to measure to plot point in space you got the side view that great atleast you can use it as a partial reference but since you didn't give yourself a front view to start with i assume it an object you have with you otherwise how did you find that the base was a circle and not a ellipse you wouldn't know just with a side view.

So have you draw alot of tilted a perfect square or just tilt a box a box and a square are not the same thing.You need a perfect square to accurate plot a point in space.

Question how would you find the point that split a circle in half if that circle is inside a square without estimating?If you can't answers this then you have a problem to accurately measure because you are eye balling always.Eye balling is great until a certain point but if you don't understand the visual rule of how to visually measure you get into trouble.The point is never to always be plotting everything it to learn to visualize the rule.

Tips for drawing perspective related exercise avoid a sketchbook get some loose cheap white paper and don't work on the shorter side but use the horizontal side of the paper this way you got more to plot vanishing point.

You doesn't need to buy printer quality paper at alll.. the idea is not to over crowd your page when dealing with perspective and to use the horizontal side to avoid distortion.

This way you avoid distortion due to not having enough space to draw them within the page or because of the lenght of the page itself. Ultimately the vanishing point should not even be on the page that when you can start to draw small thumbnail and you won't need those newbie tips once you understand more about the cone of vision.

You can learn more about visually measuring here.
https://www.youtube.com/watch?v=MOB5eKX8Y-o&t=1297s

[lvlingArtist]

I mean how do I find the flight points for this box around the upper lamp - now in green circle

[darktiste]

You don't need to make a second box you just need a bigger box that fit the object and to know how to subdivide those box.

One thing that is important to learn is to extend imaginary line vertically or horizontally from a specific point on a plane and also to be able to determine which segment vanish toward the same vanishing point as well as being able to identify segment parallel in a orthographic plan this way you can find a point inside a plane and start to create the shape within the box.

Take the more cube like form example with green pink red and blue you just need a few orthographic view such as the side,front and top view those become your plan or plane and from those you can extrapolate the form by using the square division technique detail in the previous video.

It bit complex to explain for me not gonna lie i never tried to explain such concept before.

In the example of the multicolor object the box is much bigger than necessary but it help get the idea across that those plane can be use to create an equal corresponding 3d shape it encapsule just visualize a end of one segment of that shape and extend it parallel to that shape.What you are doing in your own drawing isn't in orthographic perspective but those example use that orthographic perspective and those principle are still principle that can be apply to a 2 point perspective scenario it a bit advance to understand how those principle can translate to two perspective but once you understand it become just a question of conforming those view to one side of the box to help construct the shape.

Some tool that might be useful is a angle measuring device to find the right degree of inclination of that lamp head.

Hopeful i said enough that it translate into something useful otherwise sorry i need to simply my thinking.

As for your question as you an see in the example with the stair you can see the inclined lid of the suitcase as it own vanishing point but it as it horizontal segment vanish toward the vanishing point which are the closest to that segment if i am right.

I recommend watching this atleast it free and explain way better than me a few thing i touch on and i also recommend you draw along that extra practice that will help you for sure.

Long video on diverse perspective related rule live demo
https://www.youtube.com/watch?v=aPmrlW1QBug