27.4.14

photogrammetry test

I made a look into photogrammetry and how it could be used in a pipeline for games/visual fx.

I have done a few tests before however they were not done in proper lighting conditions.
Even this test had a few problems but they weren't anything major and they can be delt with some TLC.

So 1/2 months ago I did a short course in life sculpting. It was a great and relaxing experience.
Here's a short timelapse of my last session.


So using this as my object example. I took a images around the object. I did two methods.
I moved myself around the object 360 degrees at the same height. I did rotated the chair that the object was sitting on aswell for good measure.
This needs to be done in controlled lighting rooms to get best results. However I had a sharp sunlight coming from one side so the object would be half in darkness and half in light which isn't that great. So if I had to shoot outdoors, a cloudy weather is best.

After shooting, I took the pictures to Autodesk 123D Catch. It took several minutes to create the 3D scene.
It's a pretty good construction out of the box.




So initially I took the images all at the same height. Well that was the wrong method and I should have varied in height in some shots so I could get the top and bottom data. However cleanup would be needed no matter what. I doubt you would get a perfect outcome but at least if we make the best of the shots then cleanup would be less.

You can do cleanup in several programs, I'm not going to mention how but as 123D catch exports FBX and OBJ. It means you can get the mesh obj and the cameras aswell. So through FBX you can aswell obtain the texture for the mesh, which is pretty neat. 




Just a quick comparison of how well it's captured the form of the original object I did some quick lighting on the mesh.

HDRI :)

Original Sculpture

Digital Sculpture

It's got a lot of bumps however take note that I have not cleaned it at all apart from deleting floating meshes and obvious bits, like the nose and the chin. But overall its captured it pretty well.

For the games side, I have tried importing the mesh with texture into gameplay3D and it seems to like it :)
I was thinking of future plans of using photogrammetry for our cave environment. So making a mini set environment made out of clay. Take these as tunnels/caves and flip the normals so that we get the inside of it.
Then using the hi-res clean mesh as a normal displacement map for the low res mesh.
I think games could utilize and populate realistic objects quickly. However the process of actually capturing the objects can be time consuming. So a controlled lighting environment is a must to get optimum results.