I am trying to render 3D maps comprising of buildings and other structure using OpenLayers-Cesium (ol-Cesium) does anyone know how to do it or from where can i begin?
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I have been trying to visualize a set of individuals of different types using Ontotext GraphDB. The problem is that all of them are visualized as red circles, since they are all identified as of type owl:namedIndividual, while they also belong to more specific types - see screenshot below for an example:
I would like the different types to be visualized using different colors. Any idea what I am doing wrong?
This might sound a dumb question but I am trying to understand the basics of 3d game programming and wanted to know this thing.
I have looked at the samples here https://code.msdn.microsoft.com/Direct3D-Tutorial-Win32-829979ef and I get it how each object's vertices and indexes to those vertices are stored in vertex buffer and index buffer respectively.
What I want to understand is how would I render a scene where I have multiple objects ? How should the vertex and index buffers be set? And how should a draw called be implemented ?
A reference or an example will help please.
To elaborate on Chuck's link, the process by which you will render multiple objects will vary depending on the architecture you choose to use.
Every model is divided into a number sections equal to the number of textures/material combinations it has. Each of these sections consists of a unique texture/material combination and will have its own vertex/index buffer pair.
The reason for this is because the HLSL is primarily designed to operate on a single texture and material at a time. You bind the vertex and index buffers of a single section to the pipeline along with the corresponding texture/material, perform a draw call on it, then bind the buffers/texture/material for the next section until the whole model has been rendered.
The cool part is that you only need to load a model once. As long as you have the information for that model, you can create instances of the model using the same data but different position matricies. This lets you create hundreds or thousands of copies of an object.
My scratch codeed engine handles models like this: during initialization, a model manager class is used to load in all the different models I use and store each unique model into a model class. I then take a pointer to the model class and feed it into scenery managers which give information on what contexts the model appears in. When I populate the game world with scenery, my game tile uses a scenery list class to handle a list of instance structures and render lists. The instance structure holds information such as position/scale/orientation, an AABB, and a pointer to the model class. Each frame, I frustum cull the scenery and populate the render lists with only the instance structures of potentially visible objects and produce an instance buffer for each list to contain the positional information. Then, I can loop through each render list, assign the appropriate buffers and textures, and draw indexed instanced() to render all the copies of the model section.
I'm not sure how my process compares to other engines, but it should serve as a reasonable example of how you might handle multiple objects and then multiple instances of objects. The levels of abstraction I have in my process were chosen due to how my engine works (random world generation). The exact method you use will vary based on your application.
Here is a basic diagram showing a fairly bare-bones set up:
I have a graph G with n nodes. The graph is embedded in 2D space (so that there are well-defined angles and distances between each pair of nodes). Some nodes might be connected with edges to other nodes. Given a location L, this graph needs to be laid out on top of a map close to L, such that each node becomes a marker on a map, and such that there is a walkable path between each pair of connected of nodes. Since this will not be possible most of the time, I will allow the graph to be scaled/rotated and I will alow the distances and angles between nodes to be flexible within a certain range.
In order for me to write this specific algorithm, I would need to have some specific information about the streets near L. Does anybody know to get street data as a graph structure (so that I can get walkable paths)? I know the Google Maps API allows you to get directions between two points but I'm sure I cannot just keep getting directions without incurring any cost.
Edit: I've been reading a bit about OpenStreetMap API. It looks like this could be interesting. Maybe people can comment on this as well.
You can also check out these sites for osm and open gis data.
OpenStreetMap Extracts, here
OpenStreetMap derived data, here
GIS Datasets, here
in addition to these;
Planet.osm/diffs here
i hope it helps you...
The TIGER datasets offer a shape/line file for the USA, free. Lots of options including roads. https://www.census.gov/geo/maps-data/data/tiger-line.html
My problem is the following:
I have a map with rooms on it and i have a asp.net project where i need to insert rooms into the postgres database.
I already got, roomid, roomtitle,... but now i need to insert a polygon.
It would be pretty cool if the admin inserting the rooms could define the polygon by pressing on a map.
here is a picture of the map:
http://imgur.com/a/dgQzM
So my question is can i use something like html area coords and then use it somehow to get it into the database or am i comepletly wrong?
And what datatype can i use for the polygon in my roommodel?
Thanks
Geometric types are available in PostgreSQL. You can find polygon type represented by lists of points. Perhaps this is what you are looking for.
More details in documentation
Create struct represents point as a pair of doubles and model your
polygon as a list of that points. Once you have it you can map it to
polygon type in postgreSQL. Hope it helps.
Thanks that was part of the answer!
The only problem i habe now is how do i define the points by clicking on a map.
I have two datasets on fusion tables. One is a points layer (libraries) and the other is a polygon layer (land parcels). How do I design a query using Google Maps/fusion table to figure out this question: how many land parcels are within 1km (for example) of the library?
Also, I've seen some of the like this one where the search distance is pre-defined. Is it possible to design a query that doesn't have predefined search distances? I would prefer to have the distance undefined.
I understand that this task will require the use of javascript (I'm still a beginner), so help in that area would also be greatly appreciated.
Thanks for your help!