Photo match of a picture taken from above

photograph
matchphoto
photomatch
photomatching

#1

Hello community,

firstly, I want to say sorry for any kind of mistakes regarding language and grammar (I’m obviously a nonnative speaker) and moreover I want to say sorry for being a bit of a noob (I’m just a student so definitely no kind of professional whatsoever). At the moment I want to make a project using the photo match feature and watched several tutorials for it. My problem: all of these projects used a picture taken from the ground of a building. However, my picture is taken from above the building. My goal is to be able to build something at the height of where the roof begins (so i want to replace the roof with a new one and add another floor to it). Can someone maybe just give me a short (and I really just need a short description - if you want to write more it’s also fine) description on how to do this in this case? As a first step I added in photoshop a parallel line of the front of the roof to the back as this building has a pitched roof. But still it wouldn’t help me to get the y-axis (referring to the model of the cartesian system on https://en.wikipedia.org/wiki/Coordinate_system as in my country the calling of the axises is different) right.
The origin of the coordinate system should be the left corner corner of the building (the one in the back of those two - I marked it with a green point on the image) and how i said i want to build something on top of the building replacing the original roof with a new one (and in the end I just want to take a screenshot of it from the perspective of the original photo).
I would really appreciate it if someone could help me a bit (maybe I’m just aligning the 4 red and green lines wrong - I don’t know to be honest but tried it several times).
Thanks in advance!
noname

Edit: I just wanted to say that I have a basic understanding of SketchUp as I have used it for several projects (for example some woodwork) already. I just haven’t used the photo match feature.


#2

Your image isn’t the best for Match Photo but you should be able to get close. Take a look at my screen shot for an idea of how to set the lines. It would be nice if you had another long line in the green direction.


#3

ok, thank you very much! I really appreciate your help! My mistake was that I thought i had line the red ones on the left side (one line aiming from the back corner to the front the other one was ligned at the red line and the same accounts for the green lines). Just one small question would be is it with this matching possible to get the origin where the green dot is because how I said i need to build my stuff at the height of the roof and not the bottom of the roof.
And as I’m new to this forum: Can I somehow give you something back (like mark your answer as a good one or some sort of credit points? Because otherwise I can just tell you how thankful I am about your help.
Really: Thank you from all my heart!
noname


#4

I didn’t see the green dot you were referring to. You can put the origin anywhere but it defines the ground plane. If you put it up at the roof line of the building, anything you draw below the red/green plane will be below ground.

If you think my previous post answers your question, you can click the check mark to indicate it solved the problem.


#5

Again Thank you very much! Everything worked out well! Can’t put it in words how grateful I am!


#6

Just one last problem I’m currently facing when trying to export my model: is it possible to export the 2D rendering with all the colours/textures I gave the different planes? Because I’m seeing them when I switch the perspective but they are gone when I go back to the match photo view and also not existing on the 2D rendering. Is there any solution to this from your knowledge (as I’m feeling you’re at least kind of a professional if not even a professional user) or is it just not possible to export it with colours? Again: Thank you very much in advance!


#7

I’m not sure I understand what you mean. Can you upload the SKP file?


#8

I mean that I can give the different surfaces a color or a texture (for example there are several sorts of wood, stone, concrete… textures available to choose from) but I can only see this texture when I’m not viewing the model with my background picture (grey background for example you achieve this by tilting a bit the camera position). When I’m back in the view (or camera position) with my background picture (for example by clicking on the name of the image in the middle of the edge over the box in which I can see my model (for instance 1234.jpg), I cannot see the textures and also the models from the 3D Warehouse are just blue boxes. When I’m then exporting my work as a 2D rendering the textures still are missing. The surfaces (or planes or however you want to call the rectangles) are just plain white. Hopefully this description is detailed enough as it’s hard for me to upload any images (file size problems).


#9

I’m still not following your description for sure but I wonder if you just need to turn off the foreground image in the Styles Edit tab. Then update the style by clicking on its thumbnail in the upper left. It’ll have circular arrows over it before you update it.


#10

Ok this kind of worked out halfway last problem would be that the stone textures are not stonish (I don’t know if this describes it best - maybe I could describe it like there is no pattern) but instead is just plain grey, plain brown and so on. Is there also an option/setting that I have to check?
Last but not least and again: Thank you very much for your help this is definitely not be taken for granted!


#11

Two possibilities come to mind.

First, you don’t have Shaded with Textures set as the face style.

Second and I’d guess more likely, you didn’t properly scale the model properly. Measure an edge in the model. Is it the right length?


#12

Yes, indeed. I measured 3.3m for the length of the edge (I measured from one corner to the other) of the left wing (in the picture you’ve sent me the edge is right at the first red line counting from the top) right at the beginning of the roof top. Using Google Maps for an approximate distance gives me a distance of 12.5 meters. How can I adjust this? The only thing that comes to my mind would be the spacing that can be used while photo matching. Is this how to do it?


#13

While it is best practice to align the “match photo lines” with the key parts of the photo you wish to model, if you are in a pinch you can always take those lines from other geometry that “appears” to live in the same xy space. In this instance the foreground roof seemed like an ideal spot to take the alignment from (assuming city planning is consistent) but then to set the “origin point” at a key point on the ground plane. It’s easy to drag the origin point around prior to committing to verify geometry alignment. In this instance I was able to get an accurate model.
It also helps to drag the cursor on any of the axes (prior to “done”) to get the scale right ( or close) even though this is easily done later. A google earth view of the building can always help with scale if you don’t have that info.


#14

Also thank you very much for your detailed description that hopefully will help people browsing on the internet (as I did so before but couldn’t find an answer). As mentioned in the other comments. This problem has been solved currently I’m facing the problem that I haven’t measured it correctly and that maybe this is the reason why the textures I used (for example sandstone) are just one plain color instead of the pattern that can be seen in the preview.


#15

Ok now I’m looking like a complete noob as it worked in my other projects just fine without adjusting any settings :pensive:. Indeed the shade with textures option was unchecked. I will look up on how to properly scale the model myself as I don’t want you to help me with everything!
Thank you very much for all your help! Couldn’t be more grateful about it. Nowadays, such a behaviour can’t be taken as naturally!


#16

use the tape measure tool on a known edge length (click on each end of that line and manually add length in the “measurements box”) and when prompted, accept the “do you want to resize the model”.


#17

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