# Projection on plane

How to draw the projection of this 3d image on paper ?

I have tried using methods of projection on plane which are given in ND Bhatt book. Dimensions to be assumed by you. I have uploaded my rough try and it is front view only because I think that both side views will be same am I correct? and I am unable to make its plain view can you please provide a rough sketch for side and plain views without dimensions as I will put all the other things myself.

• You need to edit your question to: 1. Fix the title into something that tells what your question is about. (All questions on the site are about engineering design in some way.) 2. Explain what projections you want. Plan view and two elevations? 3. Show your work so far and explain where you are stuck. Otherwise your question will be closed. Jan 4, 2022 at 16:51
• Might also want to add additional tags like Drawing, Draft, Cad, etc Jan 4, 2022 at 17:02
• actually I am unable to start so please provide some hint about how to start .I use drafter and I am making these for the first time that's why I am confused .
– abcd
Jan 4, 2022 at 17:14
• You can consider that I have a bit knowledge about it..
– abcd
Jan 4, 2022 at 17:15
• please provide rough sketch or hint and further I will do
– abcd
Jan 4, 2022 at 17:22

Is this what you are asking? Below is a start.

• I will try with this start and will ask if there is any doubt and will post my previous try too
– abcd
Jan 4, 2022 at 19:17
• It's side view looks same as front view . Can you please clarify am I thinking correct?
– abcd
Jan 6, 2022 at 3:14
• Yes. In this case - a square tower (evident by the top view), all sides (front, back, left, and right side) are the same. As long as you know how to utilize the extension (dashed) lines, and draw a perpendicular baseline, then everything is getting simple, just taking a lot of measurements.
– r13
Jan 6, 2022 at 4:44
• How to know it's HP and VP as I think they are required to make a perfect drawing ?
– abcd
Jan 6, 2022 at 4:48
• What is HP, VP? Are you talking about 3D view? It is a completely different matter then.
– r13
Jan 6, 2022 at 5:37

If you are looking for an automated way what you would need to use is research homography (this is very close to the affine transformations which they also might be of help).

This is too broad to cover here (and I am not sure that its directly relevant to what you are asking) so I will just provide some links and also what you can accomplish.

## What you can accomplish

Below are two images from the documentaion of opencv.org. The initial image is a warped photo of some windows (is similar to the example in the image). The aim is to transform the image and bring the windows perpendicular to the projection plane (which can be seen in the end result).

Initial image end result

**Figure source: docs.opencv.org)

The way this is accomplished is by finding the four corners of the yellow closed polygon on the left, and map those points to the rectangle on the right. A transformation matrix is calculated from these 4 points (that's close to magic) and from that point on you can map every other pixel in the image and produce the end result on the right.

Caveat:in your case the lower side of the clock is not visible so this algorithm will produce an ugly effect.