3d scanning process and software

[stevesideas]

Does anyone know the best way to proceed with this.

I see CGaxis have a lot of scanned models of food: http://cgaxis.com/product/3d-food-ii...ion-volume-56/

I was wondering if anyone knew how they managed to achieve this ?

[joconnell]

http://www.agisoft.com/ - photoscan is what most use. You take a tonne of photos of an objects from various angles, a wide angle lens works best, and then feed it through this software. Really shiny objects cause issues as the highlights / reflections shift over the surface of the object as you change the angle you shot it from, and the software assumes that an area of detail in each picture is on the same place in the object in each shot.

You'd get better results if you got a shiny object and spray painted it with white matte paint to dull any reflections, or you can get a polarising filter for your camera lens to try and kill the reflections too. Bertrand benoit did a walk through using a free software called 123d catch from autodesk but generally photoscan is used - http://bertrand-benoit.com/blog/2012...bits-of-bread/

[stevesideas]

Thanks for the details.

[stevesideas]

Do you know where to get a rotary platform or spike where I can link it with the camera and auto snap a shot at degree intervals ? This would be very useful

[super gnu]

well you could get a cheap sculptors turntable and do the rest manually.. i dont think you need photos at degree intervals, every 20 degrees should be enough.. you would need a few different heights too.

[Neilg]

def get a polariser, they're essential. We're working on a marina film at the moment so we're buying a bunch of $50 models of superyachts to photoscan them, cause nobody makes 3d models of 200ft+ custom yachts.

After searching the internet for a rotary platform and finding nothing we wanted to spend money on, we went to a charity store and found an old ass lazy susan for $10 and marked on intervals with a marker pen. works perfect!

Good lighting and a neutral backdrop is pretty important. We do it at night, turn the lights off and have a sort of homemade softbox from the top to light it as evenly as possible

[stevesideas]

Lazy susan sounds good.

There are some diy motorized versions too but for starters this sounds ideal.

Cheers

[Neilg]

It doesn't need to be perfect, photoscan does a great job just walking around objects. We only use the markers to keep track of how far around and for a guide to keep it to 60 shots over 3 heights.

[stevesideas]

So what about trying to do the underside of the object ? Would I just turn it over and take more pics then photoscan would fit everything together ?

[Neilg]

can you hang it from wire? the very bottom of our objects arent needed, not had to face that one yet.

[stevesideas]

I guess I could try that. I'll give the trial of photoscan a go and see how I get on. Thanks for your help.

[AJ Jefferies]

You can turn the object over, shoot the underside then use Meshlab to align/glue them together. It's never 100% perfect and you'll have to do some manual clean up, but that's always the way with scanning anything (at the moment!).

+1 for the lazy susan. We got a cheap wooden turntable thing from IKEA and it works like a charm. I have a spare stepper motor from an old laser scanning rig I made (rig is a big grand, it was mostly made from Meccano ). It can be controlled via USB with some basic C programming and I've been toying with the idea of making an automated setup that rotates a platform and takes a photo. It shouldn't be too difficult to cobble together but I don't really do enough scanning to really justify it.