general adives on 3D rendering

[bogdan_otp2]

Hello to everyone!
I'm new here and relatively new to cartography as well.
Is there any software I can use that would allow me to (partially) convert a geographic information file into a 3D representation (example: to generate a 3D model of a forest on a surface marked as forested)?
Or, let's say, a software that allows to import a drawing of a layout, and then rendering it 3D?

Sorry if I'm not formulating my question right,
and thanks!

[Redrobes]

Your question is a bit vague. For the 3D model of a forest, what exactly do you mean ? Is that 3D objects of trees with branches or the overall canopy ? Or do you just want to raise up that general area.

My advice is to check out Lidar information. Those are data sets that contain a grid of heights for landscapes. You can import these data sets into some applications that can render the view in 3D but not as a model - just as a height mapped surface. You would need to extract the forested areas of it but I would say that in general forested areas in Lidar are normally just bumpy bits.

If you want to render a drawing in 3D then either you build it as a 3D model or again, create a height mapped surface. What you can do is steal bits of real world height maps from different terrain types and blend them into your map based on matching up the types to give you a height map of your map based on real world height map textures. Quite complicated.

Search this site for Lidar and also NASA has a lot of them for free. The US geological admin NOAA has some too. But I think somewhere around is a list of sources of lidar data. The UK has most of it done now and open for download and I read only yesterday that there will be a new open global map of lidar data based on the atlas satellite. So that will be pretty cool.

My blog here (link on the left) details some other methods based on photogrammetry as well but whether thats applicable I am not sure.

[bogdan_otp2]

Your question is a bit vague. For the 3D model of a forest, what exactly do you mean ? Is that 3D objects of trees with branches or the overall canopy ? Or do you just want to raise up that general area.

My advice is to check out Lidar information. Those are data sets that contain a grid of heights for landscapes. You can import these data sets into some applications that can render the view in 3D but not as a model - just as a height mapped surface. You would need to extract the forested areas of it but I would say that in general forested areas in Lidar are normally just bumpy bits.

If you want to render a drawing in 3D then either you build it as a 3D model or again, create a height mapped surface. What you can do is steal bits of real world height maps from different terrain types and blend them into your map based on matching up the types to give you a height map of your map based on real world height map textures. Quite complicated.

Search this site for Lidar and also NASA has a lot of them for free. The US geological admin NOAA has some too. But I think somewhere around is a list of sources of lidar data. The UK has most of it done now and open for download and I read only yesterday that there will be a new open global map of lidar data based on the atlas satellite. So that will be pretty cool.

My blog here (link on the left) details some other methods based on photogrammetry as well but whether thats applicable I am not sure.

I'll try to be less vague this time, but I'm just getting familiar with a lot of concepts, so please bear with me.

To answer your first point, I was thinking both ways:

- to raise up some areas. For example, polygons marked as buildings would be raised at a certain height. It's just that I want to import a file marking the polygons (since I already have one), rather than starting to draw them from scratch. I could maybe later apply further edits, to work on the details (windows, roofs, dors, etc).

- to generate 3D objects on other areas. For example, an area marked as forest would be filled by individual trees (of course, following a pattern. I don't need every single tree to be unique). An area marked as hay field would automatically be filled by hay stacks at a certain distance one from another.


To be as direct as possible: I'm georeferincing and vectorizing old maps, especially of villages. I'm considering making 3D models for better public presentations and promotion of history.
To rephrase my question: is there a shortcut from a GIS file / drawing to a 3D model?



Thank you for your suggestions and for pointing me to your blog, I'll be sure to check it out!

[Falconius]

If you have a vector file you can extrude the lines in most modelling programs. Blender included. It gives you really crappy geometry though and you may have difficulty capping things (like for buildings). You can also use a Boolean operation to then take those lines and cut a mesh (like one generated from a height map) into separate sections and have a particle system populate it with trees, or whatever. This is fairly advanced stuff though, it's not exactly simple. For things like buildings I'd suggest just tracing it out with vertices in the modelling program instead of importing the vector file, and then if extrude from those you'll get nice clean models that will be easy to cap and work with later on.

[Gamerprinter]

Well I work with 3D a lot, and yes, it can be done, but what you're asking for specifically is a height map, and a specific height map at that. Working in 3D is complex, but creating height maps is actually a lot harder to do. In a height map, the lowest elevation is black, the highest elevation is white, and all the elevations in between are vaious shades of gray. It's fairly easy to take an existing height map and use it in a 3D program, but creating a height map is actually quite difficult - I cannot do it easily. I would actually create a 3D object of the forest, and the mountains and the buildings as individual 3D objects and construct the scene out of multiple pieces of 3D objects, and render it as a final scene. I wouldn't go the route of creating a height map first. You can import 3D height maps of existing Earth terrain - those currently exist. Creating custom terrain requires specific software, which I don't have access to.

Below is a height map of a mountainous region...

GP

[Rwhyte]

If you're familiar with QGIS, there's a plug-in, Qgis2threejs, which is a great way to take 2D layers into a 3D view.

Building polygons can be extruded to their heighs by attribute. Tree points can be symbolized by 3D model trees. And in fact, trees can also be shown with 2D png images, which can do a suprisingly good job of looking like 3D objects. All these features can be placed on top of a terrain DEM as well.

Here's a quick example


If you have a polygon representing 'forest', QGIS has a tool to create random points within a polygon, and that could be used to generate 'tree' points within the forest area, which could then be symbolized by 3D symbols...

The trick would be to blend these different styles together. But, hope that can help for some ideas!

[Redrobes]

Ok I can see what your planning to do a little better now. I agree with the above. A DEM for the base is probably the easiest. Now if the resolution of the final image is quite low then you could raise up the buildings as part of the DEM. But its better if you use a vector app for the buildings. The QGIS plugin sounds like a good idea. Also, inkscape can trace out a bitmap into vector format and then usually you can import those vector traces into something like blender to make them into a 3D model. You should also check out sketchup which is particularly suited to this kind of buildings on a 3D base kind of work tho I have not used that one much. If its important for you to maintain the georefferencing then a GIS app is probably a must. Global Mapper has been used on here with some good success as well as QGIS. ArcGIS is the professional app but its very expensive and I think for what you wish to do its probably over kill unless you have a copy you can use.

[rpglandmaps]

hi..
i might be able to help with this... where is end result going to be? as i use unity games engine for terrains, but i do manualy place all trees etc as like to be in control (god like ) but unity is my end game. and with most software its about getting the data from a to b etc..