Comparing the resolutions of Matterport OBJ files
/Recently, a number of users of our Matterport OBJ conversion services have asked about the difference in resolution between the various Matterport OBJ files. So we've decided to share some analysis we did to compare them both.
Low-resolution (50k Showcase OBJ) vs the High-resolution (MatterPak™ OBJ)
The 50k OBJ is the low-resolution file that is specifically used for the Matterport Showcase. This version has some of its finer detail stripped out and compressed to reduce the overall size of the scan to ensure the showcase loads quickly and stays responsive. By comparison, the high resolution OBJ keeps all of the original detail of the scan. As a result, the file size is quite a bit bigger.
Until recently, the high resolution OBJ was available for free download by users via the Matterport Cloud Platform. Unfortunately it's no longer a free download for Matterport users, however it is still available by purchasing the new MatterPak™ bundle for $49.
As an alternative, while Matterport do not make the low-resolution 50k OBJ file available directly for download, it can be accessed using the newly released JuMP team Matterport OBJ tool (find out more about the JuMP-POP v1.0 tool from this forum thread).
Comparing the different OBJ versions?
To understand the difference in resolution between the two file types, we used a recent scan of a mechanical plant room. This scan contained a considerable amount of fine detail such as mechanical pipework, cable trays, valves, duct work.
Comparison using FBX/OBJ
Both versions of the scan were converted to FBX file using our Matterport to FBX conversion tool. Both versions were then opened using Autodesk FBX Viewer and compared side by side (see below).
It’s possible to see some visible differences in the resolution between the two images below. You might notice some patches within the left image are a bit blurrier and less defined than the right image. However, you will also notice that key detail is still visible within the lower resolution version - i.e. mechanical pipework, cable trays, valves, duct work can be clearly identified in both versions.
Comparison using Point Cloud
Another comparison was done by converting to point cloud using our Matterport to point cloud conversion tool. Both versions were then opened using Autodesk ReCap 2016 and compared side by side (see below).
The difference in resolution between the two versions is even less noticeable when comparing point clouds. The right image appears a little more crisp in some areas, but in general the level of detail appears to be fairly similar between the two. Again, you will notice that key detail is still visible within the lower resolution version - i.e. mechanical pipework, cable trays, valves, duct work can be clearly identified in both.
Results
To quantify the difference between the two OBJ file versions, we performed some analysis. This analysis considered +200k randomly sampled feature points in the low resolution OBJ file and measured how far it deviated from the corresponding feature point within the high resolution OBJ file (see below) - the results were surprising.
In the end, it really comes down to your specific use case. Using the above example, if you are using your Matterport scan to model mechanical pipework, cable trays, valves, ductwork etc. - the low resolution OBJ file should certainly be sufficient. If on the other hand you wish to model finer detail, the higher resolution OBJ file might be a better choice.
Hopefully this helps to provide some guidance to users on the different options.
More info and Links
- High Resolution OBJ File - MatterPak
- Low Resolution OBJ File - JuMP Team (find out more about the JuMP-POP v1.0 tool from this forum thread)
- Convert Matterport OBJ to Point Cloud
- Convert Matterport OBJ to FBX