Scanning with a fixed camera?

[Arahn]

Hello everyone!

As I love the capabilities of 3DF Zephyr Lite a lot, I am sad to report that I keep running into the same problem over and over again.

While using pictures made by rotating an object in front of a neutral background the software fails to align the pictures or recognize and kind of useful 3D object. The found camera positions are all over the place and the results could be best described as some kind of horrible Star Trek transporter accident.

I am wondering if I am doing something wrong or if the software just does not support such workflows. In my case rotating the object instead of moving the camera around would make my process so much easier.



Thank you very much!

[Andrea Alessi]

Hi Arahn!

You can absolutely use a turning table workflow. However, if the background has a lot of texture, what is happening is that zephyr gets confused: do you want to reconstruct the object or do you want to reconstruct the wall ? Zephyr can not know that, as you have an inconsistency between object and wall.

In order to fix this, you have to resort to masking : this way you can explicitly tell to zephyr what has to be excluded. Included in Zephyr, you can use 3DF Masquerade for this:

https://www.youtube.com/watch?v=ZIDft2_EfwI

https://www.3dflow.net/technology/documents/3df-zephyr-tutorials/tutorial-use-masking-tool/

Another solution would be to have a completely featureless background (i.e. lightbox) but i still suggest using masking anyways

[Scott Nebeker]

Yes! I completely agree with Andrea.

I'm currently working on a project that has absolute and unchanging black as the background, I'm still masking. It's not really a required step but I've found myself doing it for nearly every model because of the speed increase you'll get.

Recent Instagram post with mores but chopped images: instagram.com/p/BWlIuT8F1MO
Same post with less words on Twitter (full size images): twitter.com/scottneb/status/886324312939966464

Other useful tools for when dealing with finicky models (I believe their availability are dependent on which version):

1- Use Masquerade. You can create a mask, then apply the identical mask to the next image OR you can have it automate the process of creating a mask for each image in the series (either the next image, or ALL of the next images). This is extremely useful.

2- The "B/W Mask" toggle within Masquerade (top middle), will give a better understanding of what Masquerade is seeing and doing. Definitely toggle that on from time to time. It's like the Predator movies where you get a glance at what the monster is seeing.

3- Make use of the "Image Quality Index Tool" under Utilities at the top of the screen. You'd be surprised how much time can be saved by letting Zephyr have a sneak-peak at what you're about to give it.

Just some thoughts. If it helps, cool. If not, maybe I can help next time.


OH!!! Don't forget, if you're needing to kick-out quick models, having EVEN LIGHTING is almost a must! You'll hear about rules on how to properly conduct a photogrammetry photoshoot. Every rule is something made-up by someone. The goal is to make this quick and easy for the masses. That means that we are pushing the envelope to extraordinary degrees. Pushing the boundaries further cements the fundamentals of turntables and light-boxes. Broadening the scope is strengthening the core, if that makes sense.