Generate 2D map from 3D scene

[metalseb]

Hi there

I am currently trying to implement an A* pathfinding algorithm for a given node in a given scene. But to achieve this, I need to have the top-down 2D view of the 3D scene I am currently rendering on the screen, and I don't have any idea on how to do this. Anybody could help ?

Regards

[bal]

Check out mohaps' site as he's going to release the source of his "radar". Check the Project Announcements part of this forum for the thread about it.

[Guest]

Hi,

I have very similar problem, but I am only interested is showing a map from the top. Mahaps "radar" is showing the nodes (I've seen only screenshots), but .bsp map is a node.
So my question is how to show geometry (walls) of the .bsp map.
Is it possible ? How professional game-makers create HUD maps?

[Guest]

have a look at the split screen tutorial. Then for the top down
view change it to orthogonal mode.You could also change it to
wireframe for use in an editor etc.

http://legion.gibbering.net/mankind/ortho.jpg

[Guest]

thanks

orthogonal view is the word I was looking for. Interesting is that it seems not to render the roof of my map. Strange for me and very useful.

Wireframe mode is not the best solution because it shows every edge. Many triangles == many / lines.

To have only borders of walls I suppose I have to create special map in photoshop. Than put it in hud and over it set the user marker.

[bal]

I guess that's the way they do it in real games. Just a 2D map drawn in a image editing program (then they use mohap's way to put arrows on it). Or you could indeed use splitscreen although this will cost you some performance (twice rendering the same scene, just from a different point of view).

[mohaps]

hi the code actually is quite simple

Code: Select all

class Object
{
   vector3df positionAbsolute;
   u32 type;
}
...
array<Object*> objects;

ISceneNode* centerNode; //this is the node representing the center of the projection
vector3df centerPosition = centerNode->getAbsolutePosition();

matrix4 m = centerNode->getAbsoluteTransformation();
for(int i = 0; i < objects.size(); i++)
{
   vector3df relPos = objects[i]->getAbsolutePosition() - centerNode->getAbsolutePosition();
   m.rotateVector(relPos);

   //now relPos.X and relPos.Z contain the 2D Mapped coordinates of the object


}