exploring Photoscan, Q re setup scan

[KallenX]

Very new to this tool, Can someone tell me where i made a mistake?  I took 60+ photos of an object on a turntable however instead of it coming out with camera (pics) spread around the item, they are all from the POV of my camera on a tripod.



What did i do to make it totally fail so hard?

Thanks

[ekbmuts]

KallenX,  Without knowing much about your project, I'd say that you didn't mask your subject.  That is, the thing that you are trying to make a model out of.

It also looks like you may be trying to shoot more than one thing?  Either way:

So, go into Photoscan and open each photo in sequence.  Draw a rough marquee (box) around the subject in each image.  You DON'T need to make these marquees perfect to the edge of your subject.  Just draw a marquee around them so that they're in a box.  Once you have the marquee drawn, invert it (Ctrl-Shift-I) and hit the mask button.  That's the one up top with the two full opacity overlapping boxes.  You should end up with the subject of your photo (the thing that you're trying to make the model from) correctly lit and everything else slightly darker.

Do this for each and every photo.

There are other ways to mask, but you can read up on them later in the manual.  For now, just do this.

That will at least sort out the problem with the cameras looking like they've smashed into each other.

However, I'd recommend that you reshoot anyway and this time, fill the frame with your object if you can.  Right now, it's awfully small and Photoscan will have trouble giving you a decent model.  Either move your camera in so that it's closer or zoom in (depends what lens you have).  But you want to fill your frame with that object.  Set your f-stop to something like f16 (if you're using a DSLR camera) and make sure that every shot is in focus.

And on the off-chance that you're turning that turntable continuously with your camera on machine-gun mode, don't do that.  Frame the camera up like I said, shoot a picture.  Turn the turntable 10 degrees or so, stop it, take another picture.  And so on.  Then point your camera downwards on the object and repeat.  Then, if you have undercuts in your object, point the camera UP so that you can see under everything on the object and repeat.

That's the general idea.

But to answer your initial question,  the lack of masking is giving you the camera problems, in my opinion.

Jon

[KallenX]

That is what i suspected, however I made a mask image and tried to import it as a background mask (empty turntable) but it made no difference.  From prior research, this was all I thought I had to do.

So if i have 65 photos, i have to hand mask every single photo? That's a whole lot of work that I thought the software took care of with a background mask.  I guess I have a ton of tedious work to do.

Thanks

[KallenX]

even with masks, it's still exploding

[KallenX]

[ekbmuts]

I can't tell if you made any progress. But it looks like your cameras are correctly positioned now.

Masking is not all that tedious. You could mask 65 images in about 5 minutes.  Like I said, the masks DON'T have to be recise.  Just draw a box around the thing you want to make a model from.

The reason that you still don't have a decent sparse point cloud, in my opinion, is that your object is so small in your frame.  If you move your camera in so the object fills the frame or just zoom in if you're using a zoom lens, you'll get a much better result.

Finally, if you don't mind me asking, what is it that you're trying to make a model from? Meaning, what are you shooting? I can't tell.  If it's reflective or transparent then that's another problem you are having.  Photoscan will not return a good result with shiny, reflective or transparent objects.

Jon

[KallenX]

I think i made an inch of progress.  It is possible the issue is that the item is a plastic controller that is not matte and has a black stick. 

I will probably try again later with a matte, nonblack item.  however I still think this should work well enough, but turns out like a Dali landscape instead.

I managed to get it to at least look like the object in a point cloud, reshot the object with three sets: upper, mid, low shots which has not helped. When i try to make a mesh.. it makes a mess. or a blob to be precise.  I've put the three different sets into their own chunks, masked all 80+- photos, imported mask and aligned the photos but somehow photoscan does not show all the photos as being around the item (doing 8-10 degree turns, 360 three times). 

I've been following a number of tutorials, all of which have their examples turn out great, mine however... not so much.  I guess i spend a lot of time re-doing efforts as this software is not very intuitive or forgiving.


I was hoping at least to get a mesh out of it, i'm not even getting to the add textures part.

[ekbmuts]

Tracking.  If that object has no texture and is shiny, then it's going to be a bust.  I went through the same thing with a shiny cup and saucer with no texture.  It just doesn't work, no matter what you do.

You can purchase dulling spray in a hardware store.  But still, that won't give the item any texture and so that won't solve the problem either.

My suggestion would be to bail on the black controller and find something you can take a win at, like a nicely textured rock.  At least that will get you more familiar with the software.

I realize this can be disappointing but once you get the hang of it, you'll make amazing stuff.  Trust me.

Just stay away from objects that have no obvious texture, reflect or are transparent.

Jon

PS.  Some people go so far as to project a texture onto the object in question so that Photoscan can at least rebuild the model.  They take 2 sets of photos: one with and one without a texture and once they get to making a texture for their model, they switch out the photos. Anyway...

[MeHoo]

We use a creaform laser scanner at work.. even with that $30k+ scanner and software.. you STILL need to reduce glare with a chalk spray.. reflections will always mess up every single thing that you try to scan.  Turntables are great, but they (usually) vary the light across the object, unless, of course, your controlled lights are attached to the turntable.

I used to spray the bottles I had to model for Specalized Bicycle with grey matte paint, and even then, I had to attach random markers to the object for alignment.  Turntables are not what this software and technology was made for, and IMHO every successful scan is merely an exercise in beating it into submission in order to work.  ;p

Some have better luck.  I have limited patience and time.  I can grab the handiscan and get a usable object in ten minutes if I spray it or try and mess with photoscan settings and masking for an hour then wait for processing. 

Alternatively, I could try to scan a 150' section of an alleyway with the handiscan here in Detroit, but.. I'd get mugged, the scan would take days and more ram than any computer could handle, and photoscan did it in less than 40 hours total. so.. they have their merits.

Just something to consider... IMHO you're using a screwdriver to hammer in a nail so the best results you get are gonna take much effort on your part.

Luckily Agisoft has added in a ton of features to help.  Utilize them.  I will say though.. you need VERY diffuse lighting and no spec hits.  Your photos are the first step and 99% of the variable in this process.  As flat and consistent as you can get them, the better.

Anyhoo.. hope it helps somewhat.