Messing with photogrammetry

I was trying to apply photogrammetry to a game asset out of curiosity, I have used photogrammetry in my work experiences to build high fidelity maps and was curious about further building the skill for game asset creation. I stumbled on this tutorial:

https://www.agisoft.com/index.php?id=38


At work, I had it easy because I had the professional version which permits adding markers to the pictures to help with alignment. At home, I have the home license which doesn't have this feature, so while trying to apply photogrammetry at home I needed to learn how to use the basic tools more effectively. It looks I've been taking the background for granted and thinking that the solver would address this for me. With some experimentation, it wasn't working. A few lessons learned:

• I tried resizing the region (this was key) of interesting after the photo-alignment on 400 photos, I got a useful result! 
• I tried a few more runs with masks cropping out hud elements and this helped too. In order to apply a photomask across my 400 images, I did one, exported it as a file, and then imported it as a mask to all the 400 remaining as a file with default settings. It should also be noted that I learned the hard way NOT to apply masks to key points or tie points, this resulted in an empty mesh for me. Just use None.
• I manually deleted outlier voxels from the dense cloud to help make a meaningful mesh. This Agisoft tutorial was really well done, takes some patience to get through but you really need to see all the clicks and the reasoning behind it.

Now I'm going to try and use a smaller (80 picture) dataset, but I carefully applied masks so it doesn't look at the background so much. This didn't work =(. The background must've helped It was too sparse. I tried combining my 400 and 80 images and that didn't work either. Then I started over on my 400 image dataset that had worked well, then aligned only the 1st 100 images, then aligned the remaining 300, this went fairly fast likely due to the dimensionality being cut in half. I theorized that doing so can give me a suboptimal alignment for the 1st 100 so I reset and realigned those. Then after all 400 were aligned I did an alignment optimization function which is only available in batch options.

I have some more work skill refinement on this, but now I feel much more confident in photogrammetry, by manually massaging the data. Geez! I thought it'd be click play go! I guess this is why they say its an art.