Scanning the Blackwald Forest, Part 1

Posted by
May 4th, 2014 6:46 am

title

For this Ludum Dare we decided to leave our usual premises and rent a hut in the German Blackwald.
So why not include the location in the game?

Almost every asset in the game has been created via 3D scanning real world objects.

We used Photoscan, zBursh and Substance Designer for the process of scanning, cleaning, converting and baking. When we had everything figured out, it would take like
one hour from taking pictures to getting the asset into unity, and most of that was waiting time for processes to finish :)
We had never before done this, and it was an awesome opportunity to test that out.
We did some evaluation of tools a day prior to Ludum Dare.

Here’s what we evaluated :
+Very fast, realtime scan feedback using Scanekt.
– Low accuracy
– Low texture resolution
– needs a big distance to the subject if not using a special lens
– needs power adapter
+ Easy to use
+ free
– cloud based, requieres internet connection
– “blackboxed” , parts of the process are not adjustable
+ Easy to use
+ very adjustable ( number of points, polygons, texture resolution )
– calculation can take long if you have too many or too highres photos
So we went with Photoscan. It’s commercial software, but the beginner version is around 180$, and you can get a student version for 59$.
So how does it work?

Taking pictures :
  • Take 20-30 Photographs, while you move around the subject. The more the better. Steps must be small, there must be common features between the pictures
  • Make sure there is some perspective shift between the photographs, it will help the software to figure out the depth
  • Make sure the background of the object has enough unique features. We tried with a tiled floor, but the tile pattern wasso regular, that it confused the software,so we had to add more markers ( e.g. throw some little stones on the floor )
  • Thin objects don’t work well. We tried scanning some branches and twigs, but it always failed. Best results were always achieved be having a more or less solid pile of stuff.
  • Obviously the better the camera the better the result. It works with cheap digicams, but we used a DSLR camera.
  • Avoid reflecting surfaces or moving object ( or people walking into the photos )
You get something like this :
OLYMPUS DIGITAL CAMERA

Converting into a high density point cloud and mesh :

Process in Photoscan is pretty straight forwards. There’s a dropdown called workflow, which will give you every step you need to do. There are alot of options in these steps,

but apart from setting the desired point count we could often let everything at the default settings.

photoscan_0

photoscan_1

First thing you will get is a rough point cloud and the positions from where the picture has been taken.Magic! ( also called Photogrametry ). Here you can allready see if it’s working with your set of pictures/subject or not. Smaller holes or bumps in the scan are ok, you can fix that later on with zBrush.

Final result with this scan was 1 Million Polygons and a 4K Texture. Which we needed to get down to 3K with a 1K Map for Diffuse and Normals.

photoscan_2

In the next part I will describe what steps we took in zBrush and Substance and what we used in unity as post effects :) If you have any questions,

I’ll gladly answer them :)

Don’t forget to play our game :)

Blackwald Forest


3 Responses to “Scanning the Blackwald Forest, Part 1”

  1. Tifu says:

    Really cool, never heard of this kind of software before.

  2. ankie147 says:

    After open the website when you go to your next secondary step which is made for how we can make easy acces of the Product Data Entry and we can also discuss about all this type of the working theme. Then you can make the proceed it simply.

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