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View Full Version : Photogrammetry problem... Personal project



kyuzo
03-29-2017, 03:27 AM
Okay, so I have a basic understanding of this, and have played with programs like Icarus, photomodeler, VisualSFM, syntheyes, etc.. but I have a personal project that I just can't seem to crack.

I have some old pictures of buildings which have long gone, which I'd like to recreate. The pics are in black and white. I have no idea what focal length was used. The building I'm tackling first isn't a cuboid, but a wedge shape with a rounded front. Virtually nothing in the photos exist anymore, so I can't even get a good reference from the surroundings...

On the plus side, I do have four different images of it from slightly different angles. However, the only reconstruction I was able to get had severe distortion.

Does anyone have any suggestions of either software (ideally, free) or technique? I suspect It's is going to be a long tedious process of eyeballing it, and checking how well each view matches, and repeating over and over...

While it would be lovely if someone was able to create a low-res mesh and post it, I'm more hoping to use this as a chance to develop the skills to do it myself.

Cheers,

Derek

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Reco
03-29-2017, 03:47 AM
Try SketchUp

Lots of tutorials on Youtube.

Here is a few of them:

https://www.youtube.com/watch?v=0ey_AthZlqg
https://www.youtube.com/watch?v=2hSyw6bobpc

Reco

alexos
03-29-2017, 03:55 AM
Before photogrammetry, which given the starting material doesn't sound like a safe bet, do you know where this building was? If so, it should be relatively easy to grab a few plans from the registry office and have at least a decent starting point...

ADP.

kyuzo
03-29-2017, 03:58 AM
Cheers reco,

Must admit I had forgotten about Sketchup, but doesn't that (Like LW's match perspective) require X,Y and Z axes to be defined? I The building I'm trying to reconstruct doesn't have a 90 degree corner... And some other buildings I'm looking at doing are even worse...

I'll have a play with it though, see what kind of result I can get out of it.

pinkmouse
03-29-2017, 04:08 AM
Hmm, I doubt photogrammetry will help, it just doesn't have enough data to work on. If I were to attempt it, I'd use PFTrack, (my favoured s/w) to analyze the pic for as much info as possible, then use it's modeling functions to insert primitives into a scene to match those in the pic. Then add UV texture maps using PFTrack to the primitives, and export the model into LW Modeller.You could then use the UVs to block out the model. Very long winded I'm afraid, but until Modeller supports proper camera views for set extension/modelling, I can't think of an easier way.

gerry_g
03-29-2017, 08:28 AM
seems ironic that Newtech once did a free give away of Stitcher (long defunct I presume) as a prom upgrade offer that contained a module for photo geometry, it allowed you to trace out simple plains in different photos and the software would combine the results mapping the images to the planes as it went

ianr
03-29-2017, 09:03 AM
Kyuzo,
I find for 2.5 d buildings that the in-camera tools inside

Black Magic Design Fusion, are far superior & forgiving in editing

textures than sketch,you can precisely manipulate them time & time again.


You may find that using Fusion (there is a Free Version available) could be good

Their some good tutes out , Digital tutors (now called Puralsight) did some.

This is what you can obtain with 2.5d buildings in Fusion with pancache

https://www.youtube.com/watch?v=ET2g5f1BeEE

Your pix 4 Right-hand Side data should not be to hard to pull

out of parallax. I would pull it into shape rephoto or bake it

inside Fusion then apply to a simple recessed window mesh

with pullout window ledge polys for better definition.

As for the Curved front make a curved mesh & bake.

If the textures on the curved front don't line up, break up the arc

into small mesh sections and reapply to each part the texture.

That's the beauty of Fusion you can really keep on doing

that onto tiny meshes if needed & line them up exactly

Flip a copy of the Right hand side when done for your

Left Hand Side or Clone it. Dress & Light. et voila!

kyuzo
04-03-2017, 02:54 AM
Thanks for the suggestions guys.

I hadn't even considered Fusion... I will definitely have to investigate that further. Encouraging that they have a free edition too.

Gerry - I'd forgotten about the old ImageModeler by Realviz. Having googled it, that looks like it would have been ideal. The workflow looks just like what I want - draw a rectangular plane, snap the points to features on several images, and you're off.. Kinda like Fi's Camera match in Lightwave but on steroids. That would be my ideal method.

Bit frustrating that there is no simple reliable, affordable tool (I mean free is excellent, but there doesn't even seen to be anything in the 'couple of hundred bucks' range) to manually rebuild geometry from images. I mean Lightwave's built in camera match us okay if you have all three axes clearly visible, and same with Sketchup. For this project I only have one good rectangular plane, and it's a bit of a dead end so far as the only software that has a workflow to reconstruct it costs thousands of dollars..

As it is, I've made a start by doing a modern photographic survey of the area and trying to get a good mesh out of VisualSFM. It's pretty good, but I need to go and take more pics of certain angles, but it is a little frustrating that there is no way to manually match up features. From there I'll probably use Fi's Camera match to line up what I can see in those old buildings, and then try and build in lightwave from there. So, slow and tedious still looks like the way forward...

Derek

Reco
04-03-2017, 09:04 AM
I have Realviz ImageModeller. It is ok, but old. You will need several good quality images to get a good calibration. Based on your images, Image modeler is not the right tool.
I donít think the expensive Agisoft Photoscan will help you either. http://www.agisoft.com/

I would still use SketchUp. Itís a lot of guess work, but the result would be close. Make a grid on every single image using the brick-wall, chimneys on the building, windows etc. as a reference. Use the people as reference when doing measurements. Male=175cm.

There is no easy fix. Itís a lot of work, but you will get there.


Reco

alanestrada
07-01-2017, 11:29 PM
seems ironic that Newtech once did a free give away of Stitcher (long defunct I presume) as a prom upgrade offer that contained a module for photo geometry, it allowed you to trace out simple plains in different photos and the software would combine the results mapping the images to the planes as it went

Is there an open source replacement for that software? I vaguely remember Stitcher