Orthographic perspective

#1 I have already done an orthographic view of the scene,
the results aren't what I have suposed for my game, but I have upload the classes for anyone who wants orthographic view, They are a sceneGraph with _SetupProjection(..) changed, and a Camera with new necessary properties to the sceneGraph.

www.megaupload.com/?d=Z51EN5EQ

If there is some place to upload code, tell me and I change the links that are in megaupload provisionally.

#2 And the second thing is also done :), basically I do in code what the clasic GPU pipeline will done, World to View, View to Perspective, Perspective to ScreenSpace.
It's the robust way I think. If someone want more detailed information I can write it.

Our project is growing fast, I will put some screenshots or videos soon.

#3 Hey Ivan,

Do you mind sharing how you did the World to View, View to Perspective, Perspective to ScreenSpace?

I'm looking to achieve the same effect you are going for.

#4 Some like this (crosshairPosition is my 3D point to project):

// project to screen coordinates
Vector4 viewPosition = new Vector4(crosshairPosition - _camera.Position, 1);
Vector4 screenPosition = Vector4.Transform(viewPosition, _sceneGraph.Projection);
screenPosition = screenPosition / screenPosition.W;
Vector2 _crosshair.Position = new Vector2(screenPosition.X * _midWidth + _midWidth, -screenPosition.Y * _midHeight + _midHeight);


The hard trick was that you need to obtain from some place the actual Projection matrix (BaseSceneGraph.SceneRenderState.Projection) but SceneRenderState was protected, so I inherit from BaseSceneGraph and I create my own with a property to access this matrix;
(_midWidth, _midHeight are the screen sizes half)


Ivan.

#5 Something I forget, my camera is always looking Y+ (our game is something like a Smashbrosh clone, aka 2.5D). So I can obtain viewPosition that way.

You will have to do a coordinates transform (Translation + Rotation) to change to camera view.

Ivan.

#6 Thanks a lot Ivan!

I had no idea about the SceneRenderState, you're a life saver. I modified your algorithm to suit my camera and all is working well. If you want to check it out, I posted my solution here:

www.garagegames.com/community/forums/viewthread/84895/1#comment-586411

Best of luck with your game!