Render 3d object with screen coordinates
Author
Hey!
I wish to render my 3d objects with untransformed vertices, but be able to give the renderfunction x, y screen coordinates, and then somehow recalculate where in the world to draw the object. I don't want to care about the camera position.
I have tried to use the picking method, but it seems it doesn't really work with what i'm trying to achive.
I would like to have a function RenderObject(int x, int y) - and then have the object drawn exactly at that position on my screen.
Can anyone give a helping hand? Thanks in advance!
/Jens
You have to setup an orthographic view, here is the code in C++, you could easily change it into C#
The above code was from
If you need to read more into it.
Hope this helps.
void OrthoView(float WindowWidth, float WindowHeight){ D3DXMATRIX Ortho2D; D3DXMATRIX Identity; D3DXMatrixOrthoLH(&Ortho2D, WindowWidth, WindowHeight, 0.0f, 1.0f); D3DXMatrixIdentity(&Identity); g_pd3dDevice->SetTransform(D3DTS_PROJECTION, &Ortho2D); g_pd3dDevice->SetTransform(D3DTS_WORLD, &Identity); g_pd3dDevice->SetTransform(D3DTS_VIEW, &Identity);}The above code was from
If you need to read more into it.
Hope this helps.
Author
Thanks for the tip, but I would like to have a perspective view. Wouldn't it look flat (and boring) with a orthographic view?
A bit tricky but pretty similar to picking.
Use the x,y coordinate of the target position, and unproject it two times with a Z of 0 and a Z of 1. This gives you a ray in 3d space. Intersect the ray with a plane in a particular Z. The intersection point is your target position.
This will probably trouble you with the size (width/height) of the displayed object.
Use the x,y coordinate of the target position, and unproject it two times with a Z of 0 and a Z of 1. This gives you a ray in 3d space. Intersect the ray with a plane in a particular Z. The intersection point is your target position.
This will probably trouble you with the size (width/height) of the displayed object.
Author
How do I setup the plane I should use (which coordinates) and how do I know which Z value to intersect with?
Why dont you try rendering the object into a secondary texture... like a 256x256 texture. Then use this texture as the source for your sprite. Its a common technique.
Luck!
Guimo
Luck!
Guimo
Project() and Unproject() will work.
C# code:
C# code:
public Vector3 WorldToScreenPosition(Vector3 worldPosition){ Vector3 screenPosition = worldPosition.Project(this.CurrentDevice.Viewport, this.CurrentGraphicsManager.Camera.ProjectionMatrix,this.CurrentGraphicsManager.Camera.ViewMatrix, Matrix.Identity);return screenPosition;}This topic is closed to new replies.
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