dev in the making

game development, maya and code by brainzizi

Posts Tagged ‘zCamera

zCamera on codeplex

with 4 comments

It’s all here: http://zcamera.codeplex.com.

Please post your feedback either here, on codeplex, or on my email.
Looking for XBOX developers for testing and rewriting the code for XBOX.

Written by brainzizizi

08.17.2009 at 07:31

Posted in xna

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zCamera: Extensibility

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I like to think zCamera is very extensible. Is it really? Maybe, you’ll have to try.
The whole project consists of a really small number of .cs files:

zCameraManager.cs

The main file, inherits from DrawableGameComponent, so I can get to Game.Content and Game.GraphicsDevice for debugging purposes. Most important thing in this file is a list of all cameras of type zBaseCamera.

zVectorRenderer.cs

Vector renderer I got from www.ziggyware.com, and reworked so it’s no longer a GameComponent, but the zCameraManager takes care of it. And added support for drawing bounding frustrums.

zCameraKey.cs

The data structure used for saving keyframes. Also inludes the zInterpolationType enum for choosing position and focal distance interpolation.

Cameras\\zBaseCamera.cs

Abstract class, stores the shared fields and methods of all cameras, like position, view, projection, aspect ratio, forward vector, name, set target method, etc. If you want to build your own camera and manage it through the manager, inherit from this class. Also it contains basic debug drawing code which might also be very handy and Save/Load functions where you can save a camera using the Intermediate Serializer, and load it later as an xml converted to xnb through the pipeline, and a load function which loads raw xml files structured like the file the Save method outputs.

Cameras\\zBaseKeyframedCamera.cs

Also an abstract class, inherits from zBaseCamera and has build in keyframe support using 2 lists: List<TimeSpan> Keys and List<zCameraKey> Values. I tried using a Dictionary for this, but it just didn’t work out, due to the inability of getting a value by index, and I think this is more C++ like. Not that that’s a good thing, but I don’t think it’s gonna be a problem.

This class has support for keyframes. That means interpolation and keyframe following. I have one known bug/feature here, and that’s a bit of a hiccup when translating between the last and the first keyframe when repeat is on. The last keyframe is in fact getting linear interpolation in and out of it, because I don’t pass in the keyframes from the beginning into the catmull rom function. Maybe a little annoyance, but no showstopper.

If you want to build a cinematic camera this is the class to inherit from. Also has support for waypoint debugging and save/load

Various Helper files

Containing some helpful extension methods and interpolation functions.

And that’s about it! I’d love to post some screens but as this project is not really eye candy I’ll refrain myself.

Written by brainzizizi

08.11.2009 at 17:11

Posted in xna

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zCamera Save/Load

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Hi!

On my zCamera project, I’ve added basic support for saving and loading.
The zBaseCamera, the base class of every camera provides this interface:

public virtual SaveSettings(string path);
public virtual LoadSettings(string path);

Save is done using the IntermediateSerializer, and load is done using XmlReader to support raw .xml loading.
See, the IntermediateSerializer output needs to be compiled at runtime in order for you to load it during your game. So no save/load sessions using just the serializer.

        /// <summary>
        /// Saves the camera settings.
        /// </summary>
        /// <param name="path">The path of the file to write, without the extension.</param>
        public virtual void SaveSettings(string path)
        {
            XmlWriterSettings settings = new XmlWriterSettings { Indent = true };

            string fullPath = manager.Game.Content.RootDirectory + "\\" + path + ".xml";
            if (File.Exists(fullPath))
                File.Delete(fullPath);

            XmlWriter writer = XmlWriter.Create(fullPath, settings);
            IntermediateSerializer.Serialize(writer, this, null);
            writer.Close();
        }
        /// <summary>
        /// Loads the camera settings.
        /// </summary>
        /// <param name="path">The path of the file to read, without the extension.</param>
        public virtual void LoadSettings(string path)
        {
            XmlReader reader = XmlReader.Create(manager.Game.Content.RootDirectory + "\\" + path + ".xml");
            while (reader.Read())
            {
                if (reader.Name == "Name")
                    Name = reader.ReadElementContentAsString();

                if (reader.Name == "Debug")
                    Debug = reader.ReadElementContentAsBoolean();

                if (reader.Name == "FocalDistance")
                    FocalDistance = reader.ReadElementContentAsFloat();

                if (reader.Name == "FieldOfView")
                    FieldOfView = reader.ReadElementContentAsFloat();

                if (reader.Name == "AspectRatio")
                    AspectRatio = reader.ReadElementContentAsFloat();

                if (reader.Name == "NearPlaneDistance")
                    NearPlaneDistance = reader.ReadElementContentAsFloat();

                if (reader.Name == "FarPlaneDistance")
                    FarPlaneDistance = reader.ReadElementContentAsFloat();

                if (reader.Name == "Position")
                {
                    string vector = reader.ReadElementContentAsString();
                    Position = zCameraHelper.ParseFromIntermediateSerializer(vector);
                }
            }

I’ll release the complete source next week.

Written by brainzizizi

08.11.2009 at 07:09

zCamera keyframes and interpolation

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In my camera keyframe following project, I’m using this structure to record keyframes:

TimeSpan Key;
Vector3 Position;
Quaternion Rotation;
float FocalDistance;
zInterpolationType PositionInterpolation;
zInterpolationType FocalDistanceInterpolation;

I’m saving these in 2 lists, one containing the timespan, and the otherone containing zCameraKey (which contains other data from the previous code).

When interpolating between those keyframes you have to be sure it’s first of all smooth. This is a bit harder to achieve, considering you must interpolate 3 things: position (vector3), rotation (quaternion) and focal distance (float). The results are done smoothest with the following: Position interpolation is done using Catmull-Rom XNA built in function. Rotation is interpolated using Slerp – also XNA built in, and focal distance also Catmull-Rom. But the smoothness can be still broken with keyframes with variable distance / time ratio. Why? Because of the speed of change. This can be dealt with, but I should change my entire keyframe following system to achieve that, so I’m giving that up. The designer or whoever is setting up animation cameras should take care of that.

As the saying goes: That’s not a bug. That’s a feature.

Yeah… Because you now control the speed of change. Not some silly algorithm. If you want a smooth camera that doesn’t care about the spacing of the keyframes, use Graphic Runner’s Camera animation @ http://graphicsrunner.blogspot.com/2008/05/camera-animation-part-ii.html.

Also I frapsed some keyframe following action in low res on youtube, check it out: http://www.youtube.com/watch?v=seUiYPo_V1k

Also a couple of the latest screens from zCamera:

Written by brainzizizi

08.09.2009 at 21:00

Posted in xna

Tagged with , , , ,

zCamera

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I’m having a blast playing with camera code in XNA. This is the third time I’m writing my own camera, and after I experimented a bit with various camera implementations including Quaternion rotation, Matrix rotation, frame-by-frame rotation, I can now say that I get the basic principles of every camera. And my goal is to make a light camera framework, with a couple of build in cameras and code for easier writing your own camera. Last night was really productive, as I wrote some messy debug code using the vector renderer component from Ziggyware which I’ve tweaked a bit to draw bounding frustrums and alike.

I’ll release the source when I write some more camera types, but first a couple of screen shots:

The package will consist of two projects: zCamera and zCameraPlayground which uses an early version of zGui, my gui framework for debugging purposes.

PS.
The model I used is the model from XNA’s Normal Map sample. If you see a problem in that, please leave a comment.

Written by brainzizizi

08.08.2009 at 12:22

Posted in xna

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