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Index › Programming Questions & Help › OpenGL and 3D Libraries › converting p3d perspective calls to opengl
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converting p3d perspective calls to opengl (Read 1065 times)
ekenei
converting p3d perspective calls to opengl
Feb 6th, 2010, 2:40am  
how would i convert thse opengl calls to p3d?

gl.glMatrixMode(GL.GL_PROJECTION);
gl.glLoadIdentity();

glu.gluPerspective(1f, 1f, .001f, 10000f);

gl.glMatrixMode(GL.GL_MODELVIEW);
gl.glLoadIdentity();

i thought it would've been

perspective(1f, 1f, .001f, 10000f);

but that's not working.
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V
Re: converting p3d perspective calls to opengl
Reply #1 - Feb 6th, 2010, 7:29am  
processing works with radians, opengl works with degrees

perspective( radians(1f), 1f, .001f, 10000f );
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Victor Martins | www.pixelnerve.com/v
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Quark
Re: converting p3d perspective calls to opengl
Reply #2 - Feb 6th, 2010, 8:27am  
V is right about the radians and the parameters for both glPerspective and Processing's perspective(0 are the same.

The first parameter represents the vertical field of view but in

Code:
glu.gluPerspective(1f, 1f, .001f, 10000f);

you have it as 10 where a value of 600 is more likely.

The second is the aspect ratio of the window and is calculated as width/height so 1f is fine for a square window.

the last 2 values are the near and far Z values.

I suspect that you need to increase the Y fov.

You should also be wary about using P3D as there is a bug in the clipping routine which means you can get grossly distorted rendering especially if there are objects to behind the view point.
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ekenei
Re: converting p3d perspective calls to opengl
Reply #3 - Feb 6th, 2010, 9:44am  
thanks! thats a big different. and yes ive been finding some bugs in doing opengl in processing and vice versa so ive been making two drawing modes for all the draw calls ive been making so i can change between p3d and opengl depending on what im doing...
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ekenei
Re: converting p3d perspective calls to opengl
Reply #4 - Feb 6th, 2010, 10:11am  
also how would i convert these opengl rotation calls to p3d?

gl.glRotatef(-_phix, 1, 0, 0);
gl.glRotatef(-_phiy, 0, 1, 0);
gl.glRotatef(-_phiz, 0, 0, 1);

i thought it would've been

//rotate(float angle, float vx, float vy, float vz)

parent.rotateX(PApplet.radians(-_phix),TWO_PI, 0, 0);
parent.rotateY(PApplet.radians(-_phiy), 0,TWO_PI, 0);
parent.rotateZ(PApplet.radians(-_phiz), 0, 0,TWO_PI);

or

rotateX(radians(-_phix));
rotateY(radians(-_phiy));
rotateZ(radians(-_phiz));

but neither are working...
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