Tagged Questions

0
votes
1answer
46 views

What values to construct “Projection Matrix” from?

I am curious to what standard values I should use to create a camera's projection matrix, as well as if certain measurements need to be taken if I want to represent a very small world or a very big ...
3
votes
2answers
65 views

Extract smaller frustum from camera frustum?

Background: I was thinking of implementing multiselection by performing a frustum culling on a sub-part of the screen. Problem: Given total screensize, a rectangle on the screen (pos, size), and ...
1
vote
1answer
45 views

3D Camera raytracing (PSM SDK) [duplicate]

I am currently creating a 3D Camera on the Playstation Mobile SDK (which is basically openGL with just a little bit of abstraction). The game I am trying to make is a 3D Tactical. That means my world ...
10
votes
2answers
580 views

Why is 90° horz / 60° vert the default FPS Field of View?

As far as I understand it, vertical Field of View should be adjusted to: fov = 2 * arctan(0.5*screenHeight / distanceEyeScreen); That is, Field of View should match a user's distance to and size of ...
1
vote
2answers
107 views

Accumulating rotations for camera

It seems there are three ways to store a camera's rotation: in angles, view matrix or quaternion. I was using euler angles since when I used a matrix it had a tendency to accumulate rounding errors ...
1
vote
1answer
73 views

XNA 3D coordinates seem off

I'm going through a book, and the example it gave me seems like is should work, but when I try and implement it, it falls short. My Camera class takes three vectors in to generate View and Projection ...
1
vote
3answers
685 views

2D camera perspective projection from 3D coordinates — HOW?

I am developing a camera for a 2D game with a top-down view that has depth. It's almost a 3D camera. Basically, every object has a Z even though it is in 2D, and similarly to parallax layers their ...
3
votes
1answer
260 views

Panning a 3d viewport in 2d direction with rotated camera

I am using below code to pan the viewport (action script 3 code using flare3d framework) _mainCamera.x-= Input3D.mouseXSpeed; _mainCamera.z+= Input3D.mouseYSpeed; Where as Input3D.mouse[X|Y]Speed ...
0
votes
1answer
237 views

3d world vertex translation to go to 2d screen coords

My technical english is a little rusty so to avoid misunderstands please be patient with me :) I will try to be brief and clear Situation: - I have a 2d sprite character on the screen - I've just ...
0
votes
1answer
746 views

as3 3D camera lookat

I'm making a 3D camera scene in Flash, draw using drawTriangles() and rotated and translated using a Matrix3D. I've got the camera to look after a specific point, but only on the Y-axis, using the x ...
-1
votes
1answer
150 views

Camera not working

I made a camera in DX9. To move forward I press the Up arrow. To rotate on the Y axis I use the mouse. When I perform these movements on their own the camera moves at the speed I want. However, if I ...
2
votes
1answer
372 views

3D zooming technique to maintain the relative position of an object on screen

Is it possible to zoom to a certain point on screen by modifying the field of view and rotating the view of the camera as to keep that point/object in the same place on screen while zooming ? Changing ...
2
votes
2answers
579 views

How to rotate an object so it stands correctly (back always facing the camera)

I have the following scene: And I have two 3D vectors, the camera position, and the focus position. The focus vector is always behind the monster. I know how to rotate the camera around the focus ...
1
vote
0answers
475 views

How to turn a 3d camera (in HTML5 2D Canvas)

A few years back I started experimenting with 3d in canvas. Everything went pretty well untill I had to to turn the camera, I couldn't get it done. A few days back I just happened to stumble upon ...
1
vote
3answers
2k views

3D XNA Tracking Camera

I'm trying to implement a camera that tracks a 3D model in my game. I've taken a look at this MSDN article on creating a 3rd person camera, as well as experimenting on my own; but I don't get the ...
3
votes
1answer
404 views

Perspective projection with 90 degrees between X-Y axis?

I'm trying to create a game that mimics Tibia's projection style: , As you can see, a 3d point is mapped to 2d like this: So I've downloaded Three.JS and a lib to create a Orthographic Camera. But ...
2
votes
2answers
214 views

How does Wii detect user's movement with its camera?

I try to understand the concept behind Wii device. It has 4 camera with capture user's movement, I wonder how does these cameras work? Any reference, article, or papers would be great source for me to ...
5
votes
3answers
648 views

What's a pre-multiplied 4x4 matrix?

I'm using a 3d game engine, that uses a 4x4 matrix to modify the camera projection. The matrix is in the regular 4x4 format: r r r x r r r y r r r z - - - zoom The description for the ...
4
votes
1answer
603 views

How can I achieve a zoom-like camera effect?

I have a top down 3D camera: view = Matrix.CreateLookAt(new Vector3(0,0,20), Vector3.Zero, Vector3.Up); Now I want to achieve the effect like when I zoom in the scene and only show a section at the ...
2
votes
2answers
719 views

Why is my quaternion camera rotating around strange axes?

I can't get it to work for the life of me. Its rotating the camera in the global coordinate system, or some other random coordinate system, not the camera local coordinate system. WASDEC work ...
3
votes
1answer
1k views

Can a 4x4 matrix describe a camera's perspective?

I'm working with a closed-source 3D engine, and it only allows you to set the view projection via a 4x4 matrix. Can this matrix describe the camera's translation, rotation & perspective? I turned ...
2
votes
1answer
415 views

Smooth Camera Rotation around 90 degrees

I'm developing a third person 3D platformer in XNA. My problem is when I try to rotate the camera around the player. I would like to rotate (and animate) the camera 90 degrees around the player. So ...
1
vote
1answer
2k views

OpenGL 3D Camera

And here I am again, looking for help with my OpenGL camera once again. This is starting to get embarrassing. Anyway, here's the deal: I think my OpenGL First Person free roaming camera is starting ...
0
votes
1answer
303 views

Conversion from matrix defining rotation and position to camera matrix

I have a matrix that defines the rotation and translation of an object, relative to (0, 0, 0). Assuming that the identity matrix defines the camera to be at (0, 0, 0) pointing at (0, 0, 1), how would ...
5
votes
2answers
453 views

Recommended 3D camera settings and model sizes for an FPS

I'm making a simple FPS and I can't decide on the size of my models and my camera settings. Could someone please recommend a good combination of: camera field of view near and far planes model ...
2
votes
1answer
226 views

Why doesn't the y Axis work with SuperBible frame reference or GluLookAt

I'm currently trying to understand how to use the GLFrame Class in the superbible book, and acording to the 4th edition of the book, the camera matrix derived from the Frame of reference class should ...
6
votes
4answers
835 views

Equation for bouncing graph?

I basically want my camera in 3D move automatically. Currently, I have linear movement which is rather dumb, so I'd like to do a bouncing movement. However, what is a good equation for bouncing? I ...
4
votes
1answer
308 views

Handling cameras in a large scale game engine

What is the correct, or most elegant, way to manage cameras in large game engines? Or should I ask, how does everybody else do it? The methods I can think of are: Binding cameras straight to the ...
3
votes
2answers
294 views

How do I get started with fog type effects in a first person game?

Hey guys, I'm currently using JME3 to learn 3d game development in java, and I have run into a situation. I would like to add fog effects to my games, but I don't even know where to start to implement ...
1
vote
2answers
562 views

How do I have to take into account the direction in which the camera is facing when creating a first person strafe (left/right) movement

This is the code I am currently using, and it works great, except for the strafe always causes the camera to move along the X axis which is not relative to the direction in which the camera is ...
2
votes
1answer
838 views

Obtaining a world point from a screen point with an orthographic projection

I assumed this was a straightforward problem but it has been plaguing me for days. I am creating a 2D game with an orthographic camera. I am using a 3D camera rather than just hacking it because I ...
5
votes
3answers
3k views

Why / how does XNA's right-handed coordinate system effect anything if you can specify near/far Z values?

I am told repeatedly that XNA Game Studio uses a right-handed coordinate system, and I understand the difference between a right-handed and left-handed coordinate system. But given that you can use a ...
3
votes
1answer
4k views

3D Ray Casting / Picking

I am not sure if I should post this link, but I feel this falls into game development just as much as it does math. I have a ray cast's far and near values and I am trying to calculate the end point ...
4
votes
1answer
366 views

3D Camera Problem

I allow the user to look around the scene by holding down the left mouse button and moving the mouse. The problem that I have is I can be facing one direction, I move the mouse up and the view tilts ...
3
votes
2answers
1k views

3D camera implementation

I've been bashing my head against the concept of a 'camera' for my 3D world for some time now, and I'm not sure I'm doing this right anymore. Maybe I've been working on this for too long and have ...
2
votes
2answers
2k views

Camera field of view: 3D projections & trigonometry

Okay, here goes. I have a camera at (Xc, Yc, Zc.) The Xc and Yc coordinates are latitude/longitude, and the Zc coordinate is an altitude in metres. I have a point at (Xp, Yp, Zp) and a field of view ...