re-creating landscapes (pre vs post civil works)

Support Modeling
#1

Hi, I’m brand new to blender but I think it is the right tool for what I want to do. I want to be able to generate a landscape showing before and after certain proposed civil works projects (say a new road, or a new dam). Nothing pressing at the moment - just building up skills. Say for a proposed (not built) new dam development, the information I would have would be:

  • topography of whole area as a mesh surface
  • aerial photograph (looking vertically down)
  • perhaps an oblique site photo or two (taken from hill or other vantage point)
  • mesh design of the dam (from sketchup or autocad)
  • the new water level and where this would intersect the topography
  • details of any areas that would be affected by landscape changes such as vegetation replanting, etc.

I would want to generate a series of still images from various vantage points showing the likely change in the landscape as realistically as possible, but all generated within a virtual scene (not photoshop collage, etc.). Possibly even a fly-through? Typical existing ground cover would be mixture of rural grazing land, sparse and dense forest with maybe one or two distant buildings (say a farmhouse). [edit: I’ve attached a couple of pictures put together just in sketchup using the terrain, aerial photo and mesh model… obviously trying to improve on this a lot by using blender].

I was wondering if anyone could point to some good tutorials on how I would go about integrating this sort of information. Or failing that, even some dot points on how you would go about it?

Thanks heaps

  • Mick -

From sketchup.JPG1061×433 79.3 KB

Draped aerial.JPG1199×655 159 KB

#2

[ATTACH=CONFIG]209263[/ATTACH][ATTACH=CONFIG]209264[/ATTACH]

Here’s some pics to help explain. An example of aerial photograph on topography and with a hypothetical dam and impoundment in the river valley - just put together in sketchup. I want to be able to provide semi-realistic images. Probably would need the trees in 3D (for closer up images).

#3

Since you’re new I’d just watch some videos on CGCookie to get the feel of how the Blender workflow is, and the kind of things it does. There isn’t anything you listed that I don’t think it could handle though.

There are several ways to handle terrain. Probably the best in your case is using a heightmap/displacement texture. It’s a black and white texture you assign to a plane, and it distorts it based on the value (white parts are really high, dark parts are really low). Then you can easily modify the terrain, by just repainting the textures.

Unfortunately, I can’t seem to find a non-crappy tutorial on doing it even though it’s a common technique. This BlenderGuru one he does it with the tracks in the snow if I remember. There are a few others on YouTube if you search, but like I said results may vary. :confused:

#4

I think the main problem is to import a good topography to Blender. I mean, you can use sketchup to import a topography mesh from google earth, but that topography is not very good. It is not accurate (too smooth, flat). If you find a good digital topography file, probably is a CAD file showing lines or contour with different levels. Transform that one into a surface and a mesh is a bit difficult. If the intention is just illustrative you can made a fake topography. But, if your idea is a test to predict the extension of the lake, you’ll need another program to translate the topography file into a mesh to export it in Blender.

#5

If you google for something like this: “geographic data import 2012 site:blenderartists.org” there are several threads to look into for some scripts, links to software and data related to this.

#6

Hi! thanks for the replies. I think I haven’t provided enough information…Regarding the topography I’m pretty confident as usually we have aerial laser survey data, which creates a point cloud that I can get a TIN mesh from in autocad then export/import to Blender, so this is probably the only area that I think I’ve got sorted. I guess the real thing I’m really asking about is about adding trees since there’s just so many in a landscape - how (and is it even advisable?) do I add vegetation to such a large area so that I get the realistic feel? Is there a semi automated way of sprinkling trees into the areas that I know are heavily forested, and then less in the other areas? I’ve watched a few tutorials on textures/materials, so I think I’ll be OK with basic ground cover/grass, but I’m pretty sure I need 3D trees. Is this how most of you would approach such a problem? Also water textures/materials for a large dam? Lighting tricks? My problem is that I don’t know enough yet to know what to ask, so was hoping there might be some “create a landscape” type tutorials out there.

Thanks

  • Mick -
#7

I just recently modeled a pretty intense bit of a mountain range from topography maps. Wasn’t easy, but once the topography lines are set up, it was an iterative process of shrinkwrapping a subdivided grid to the topo lines, projecting another grid over that mesh (for cleaner lines), subdividing + shrinkwrapping THAT to the topo lines again, etc. etc. and finally decimating the whole lot a bit in order to make a more efficient mesh. Turned out quite well and accurate enough for site studies + compositing with photographs, etc.

To add changes or more detail, it’s quite easy to mash it up with Dynamic Topology sculpting and displacement. A lot of topo lines are interpolated / made up anyway, so it can be a bit tricky to match things perfectly to existing conditions.

#8

Hey thanks guys. @eppo - that’s a pretty helpful thread on the veg… I’ve downloaded the file and am exploring that - don’t fully understand it, but has a lot of features I’ve got questions about… great link.
@stompin tom - that sounds pretty laborious. Do you using a contour map? One thing that may have helped in that case is sketchup - where you can either import or trace the contours (if you only have a picture), set the elevations and create a surface from the contours. The resulting surface isn’t perfect but it’s quick.

I’ve noticed a few weir things importing my topography mesh from sketchup - collada format seems pretty hopeless, but 3ds works pretty well.

Back on the veg: is there someway to govern the distribution of vegetation, similar to the topography method mentioned by xrg? i.e. using a greyscale texture to control the density of individual instances of trees? I’ve got this idea of using the aerial photograph and painting in white for dense forest, black for nothing, and lots of greys for in between and then using that?

#9

you can use weight paiting to control where verg will be added and what type !

salutations

#10

Here’s some “how to tackle it” image and file to play with

mp_howto.jpg1115×999 571 KB


http://www.pasteall.org/blend/18513
Hope helps, HNY btw too!

#11

Eppo - thankyou - lots to learn from this one ! Perfect
Regards

  • Mick