[SOLVED] 3D HUD Positioning

Engines, Libraries and Tools Java 3D
#1

Hello.
I was rending my hud graphics ontop of the canvas, but as explained in a previous thread; this was too much of a performance hog.

So I’ve converted to using seperate QuadArrays for each hud component. By doing this, I am having trouble positioning the components in the scene.

Meaning, how do I know where the edge of the screen is inside of the canvas? With the previous method (drawing ontop of the canvas), I could get the size of the Frame to determine where the components were placed.

Is there a way to do this in J3D? I now this should be dependent on the Z coordinate. Has anyone figured this out before?

Thanks

#2

So the placement of the components (and their sizes) is dependent on the aspect ratio of the screen (rather the sizes should be dependant).

So what I did was the following:

  • All components’ positions and sizes are relative (from 0.0 - 1.0).
  • Find the aspect ratio
  • set size and position based on aspect

Here is how I found out the aspect ratio


For 4:3 then resx/resy*3 == 4
For 16:9 then resx/resy*9 == 16

Now we set the size of the components (lets say our aspect is 4:3)
then


component.width3d = component.width*4f
component.height3d = component.height*3f;
component.pos3d = new Vector3d(component.x*4f,component.y*3f,0f);

We also have to set the z-axis for all the components. You can do this a number of ways. I choose to put all my components in a TransformGroup and then move that group’s position.
For the way I have things setup, the vector I used to move the group is


[-2f,1.5f,-5f]

So for 4:3, I based my screen size off of the width being 4 and the height of 3 (meters).
Because 0,0 is in the middle of the screen (as opposed to awt were that coordinate is on the top left), we need to adjust.
So we move everything over by half of the dimension (IE half of width is 2).
As for the Z-axis, I just got this number by trail and error.