Cave: Searching for Australia's Forgotten Beasts - Day 5 - Mapping the cave
Video | Updated 2 years ago
This video explores the technologies that can be used to map and recreate the cave environment in 3D.
Sam Arman: OK, well the reason we are undertaking this survey is so we can understand the context behind all this fossils that we’re looking at, so we really need to understand how the fossils relate to the cave and to the sediments within the cave. So what we are doing here is we’re actually recreating the cave. So what you see here is the actual… first you see the solution part that we came down to get into the cave. Then you can sort of stroll across the rock piles as we’ve done numerous times throughout the trip and then you sort of see the cave floor itself. Now what I’ve done here is started to model the actual cave floor. So you can see over here, you can see that sort of flat area where all the sediments are panning out, and as well as that you can see these two pits. Pit A which sits below the stalactites that Minh’s going to show us about in just a second, as well as Pit B where the eagle was pulled out this morningDid you want to show us a bit about what you are doing with the stalactites?
Dr Minh Tran: Sure, this is just one example of how you can reconstruct objects from images and I’ve taken two photos were are slightly separated and parallel, and it produces a 3D mesh as a result, and it also produces textures.
Sam Arman: I guess the big thing now is just trying to combine these two methods, because this is essentially just data and you’ve got a lot more detail.
Dr Minh Tran: Yes, if you can export that into a format where I can import that into Blenda, because that’s what I use, and then I should be able to merge the two images and then I can do a bunch of partial reconstructions and have that in say, OBJ or something. And if you can export it something I can read then I can consolidate the two.
Sam Arman: So you can basically just take that reconstruction of the detailed areas and put that on top of the…
Dr Minh Tran: Yes, because this is quite low res… well it’s a coarse reconstruction, so I can make a higher res reconstruction, and it would be good to actually use this, because as you are moving through the different areas of the cave, if you can’t see it, then you don’t need the detail there. You only need the high resolution images in the areas that are being rendered. So I think we can use that pretty well.
Sam Arman: Alright, sweet.
Dr Minh Tran: Do you the distance measurements as well?
Sam Arman: Yes I do, let me pull that up.
Dr Minh Tran: Because they’re really handy.
Sam Arman: So the width of the cave itself is 60 meters, no 30 meters, and the width is about 60 meters.
Dr Minh Tran: So are the 3D points to the nearest centimeter?
Sam Arman: They quote sub millimeter, but they are not quite that accurate.
Dr Minh Tran: So one point would be… Where’s the origin defined relative to?
Sam Arman: It’s defined relative to the four stations in I used and set-up throughout.
Dr Minh Tran: So then each one would have a set of points, because you’ve got a set of layers and each one would have their own origin. Is that right?
Sam Arman: Yes but they’re all interrelated, so it’s all part of the main survey.
Dr Minh Tran: OK.
Sam Arman: What I’ll do, as I finish up surveying I’ll take it back up to the original point then I can work out how much actual error I’ve developed through the survey.
Dr Minh Tran: Alright. OK.