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Main forum => Bug Reports => Topic started by: MrTAToad on 2012-Feb-23

Title: 3D Display problem ?
Post by: MrTAToad on 2012-Feb-23
I have my 3D camera at 0.0,30.0,0.0 -> 0.0,-100.0,0.0 and for some reason nothing is displayed.  Change the Z value to anything and all the objects are displayed for some reason
Title: Re: 3D Display problem ?
Post by: mentalthink on 2012-Feb-23
Perhaps whit this values you are into the 3D objetcs... and if the normals not are displayed in both sides perhaps it´s this...

The diferender of the y in the camera and the Target not it´s too much

0.0,30.0,0.0 -> 0.0,-100.0,0.0

Another thing... I don´t rebember if it´s the same case than you, but try something like this...
0.1,30.0,0.0 -> 0.0,-100.0,0.0

Only change a little the parameter them are equal... I rebember I have trobles whit this... some similar to my post about (Rgb(x,x,x))
Title: Re: 3D Display problem ?
Post by: Slydog on 2012-Feb-23
Strange.  So you're looking straight down, in the center of the world (x,z)?
Is this related to some kind of 'gimbal lock' style bug?
Maybe the 'camera up' vector is screwed up?
For an experiment, you could try adding this before 'X_CAMERA':
Code (glbasic) Select
X_CAMERAUP 1,0,0

Ha, I really have no idea what this will do, just throwing out some debugging ideas.
But, you'd still thing GLBasic should handle this situation.
Maybe Gernot could detect this situation, and slip in a '0.0000001' for one of the x or z values.
Title: Re: 3D Display problem ?
Post by: MrTAToad on 2012-Feb-23
Quote from: mentalthink on 2012-Feb-23
Perhaps whit this values you are into the 3D objetcs... and if the normals not are displayed in both sides perhaps it´s this...

The diferender of the y in the camera and the Target not it´s too much

0.0,30.0,0.0 -> 0.0,-100.0,0.0

Another thing... I don´t rebember if it´s the same case than you, but try something like this...
0.1,30.0,0.0 -> 0.0,-100.0,0.0

Only change a little the parameter them are equal... I rebember I have trobles whit this... some similar to my post about (Rgb(x,x,x))
The trouble with using a non X or Z value is that, whilst everything does look fairly straight, you can see it is at an angle...

QuoteStrange.  So you're looking straight down, in the center of the world (x,z)?
Is this related to some kind of 'gimbal lock' style bug?
I was wondering that too

At the moment, I'm doing it along the Z value instead - had to rotate my graphics, but aside from that it works okay.

Title: Re: 3D Display problem ?
Post by: Marmor on 2012-Feb-23
also play with camerarange
Title: Re: 3D Display problem ?
Post by: kanonet on 2012-Feb-24
Can not confirm your problem, you camera coordinates work for me. maybe you need to take care, that your objects get in range?
Title: Re: 3D Display problem ?
Post by: MrTAToad on 2012-Feb-24
Oh yes, it's all in range and will display when the Z value is set to something like 0.1

Another problem - is X_SCREENTOWORLD working properly - it seems to be returning values that have no real relation to actual 3D coordinates :

Quote-1.384185482e-002
-1.384185482e-002
-1.012185649e-002

When the actual coordinate should be around -15 and -11
Title: Re: 3D Display problem ?
Post by: kanonet on 2012-Feb-24
Oh i just realized that i tested with X_CAMERAUP, in this case it is working (just set it to 0,0,1 or 1,0,0). Without changing the camera up vector it doesnt show any object. Changing the up vector is better than adding an offset.
Title: Re: 3D Display problem ?
Post by: MrTAToad on 2012-Feb-24
Yes, I'll probably have to use that.

SCREEN2WORLD is being a bit odd.

If sz<0 then I get a decent range of positions, but the step value between then is well over double the width of the object for some reason...
If sz>0 then I get the very small x and y positions...

Title: Re: 3D Display problem ?
Post by: matchy on 2012-Feb-24
I've always had to move the camera target by a fraction to get a top view.

Code (glbasic) Select

X_CAMERA 0.0, 30.0, 0.0  ,0.001, -100.0, 0.0


Title: Re: 3D Display problem ?
Post by: UBERmonkeybot on 2016-Jan-24
I just came across this problem.