proscene camera damping

lllluj

in Contributed Library Questions • 1 year ago

Hello,

Part of upgrading the ANAR+ library to v2.0, I would like to have a little damping (smoothing) effect on the camera when using proscene. That is the mouse update should define a target view which is then reached by interpolation. For instance with

myCamera.interpolateTo(Frame f)

Since proscene has a lot of interpolation capabilities, I suspect it may be doable. The only thing which is unclear to me is to construct a target Frame from the mouse interactions without having the camera move. Looking at the example and the javadoc did not give me definitive answers.

Maybe having two cameras one detached from p5 camera and the other attached and doing the interpolation, using

attachedToP5Camera();
detachFromP5Camera();

But how is it possible to specify which Camera gets the mouse interaction?

Any clue someone?

Replies(9)

nakednous

Re: proscene camera damping

1 year ago

Hi,

I'm flattered that you're using proscene to develop ANAR. At first glance your issue seems not that straightforward: some iFrame and iCamFrame methods would need to be overridden which seems not that neat to me.

I'd prefer to add this feature to proscene itself. I hope you don't mind to wait for it. The next major release should be in synced to that of P5, but I hope to add the new feature in some alpha/beta release and let you know here for you to test it.

lllluj

Re: proscene camera damping

1 year ago

Hi,

Thank you for your kind reply. I recently realized that there was no point trying to develop a camera as good as yours since it now exists. It was suggested by Gennaro Senatore from Expedition. The only strange thing is how long it took me to go ahead and include it in ANAR...

Therefore I really don't mind to wait. I'd be glad to test the feature and update the code as soon as the damping is available. I find a very slight damping makes everything smoother especially with heavy geometries...

I have another question: I wanted to have some CAD like camera, namely with the horizon always straight (no rolling). I tried to do it with a Constraint but could not find a proper quaternion constraint that does that. What I ended up doing is the following (excuse the mess in the code this was done in a rash):

class ANARinteractiveFrame extends InteractiveCameraFrame {

        public ANARinteractiveFrame(remixlab.proscene.Camera cam) {
            super(cam);
        }

        public remixlab.proscene.Camera camera() {
            return camera;
        }

        @Override
        protected Quaternion deformedBallQuaternion(int x, int y, float cx, float cy,remixlab.proscene.Camera camera) {
            // Points on the deformed ball
            float px = rotationSensitivity() * ((int)prevPos.x - cx) / camera.screenWidth();
            float py = rotationSensitivity() * (cy - (int)prevPos.y) / camera.screenHeight();
            float dx = rotationSensitivity() * (x - cx) / camera.screenWidth();
            float dy = rotationSensitivity() * (cy - y) / camera.screenHeight();

            PVector axisX = camera.frame().transformOf(camera().frame().inverseTransformOf((new PVector(1,0,0))));
            PVector axisZ = camera.frame().transformOf(new PVector(0,0,1));

            float angleZ = rotationSensitivity()*(dx-px);
            float angleX = rotationSensitivity() *(dy-py);

               //left-handed coordinate system correction
            if( scene.isLeftHanded() )
                angleX = -angleX;

            Quaternion quatZ = new Quaternion(axisZ,angleZ);
            Quaternion quatX = new Quaternion(axisX,angleX);

            return Quaternion.multiply(quatZ, quatX);
        }
}

My question is then is that the right way to go or is there a better way of doing it?

Note that I ended up overriding some other function to tweak some mouse controls (namely the zoom wheel the other way round) so I am ok with the current solution. Just for the sake of curiosity.

One comment I may add: I would find the possibility to create a specific shortcut or mousbinding very handy. For instance for defining top front side views with corresponding camera constraints, something a bit more constrained than ALIGN_CAMERA. For now I have to add my own keypressed checks on top of it and it spread the definition over the code.

Maybe it is already possible or there is a cleaner workaround. But I couldn't find an easy way to do it.

Also I have always thought that switch statements are much slower than if {} else if {} chains, despite their lack of readability. Since you use these quite extensively, may I ask if you noticed a difference yourself?

you can have a look at the current work (super alpha) here (much of the examples don't work, you have to figure out one that does...)

http://anar.ch/img/ext/ANARversions/test/ANAR.zip

Thanks again for the good work. I really like the camera.

PS I am the one who spams (irrelevant?) issues on google code... the last one:

http://code.google.com/p/proscene/issues/detail?id=7

nakednous

Re: proscene camera damping

1 year ago

I tested it and I'm not not totally sure (maybe it's just me testing scene), but it seemed to me a bit like this one: http://forum.processing.org/topic/peasycam-conical-movement ? Otherwise, could you please give me some url (video or app) where the feature is shown (think I've never seen this behavior before)? Is it already part of the anar alpha you pointed me out?

Currently there's no mechanism to deal with user-defined actions. In part it was a design decision to simplify things out in proscene 1.x., e.g., as you probably have already seen, actions are defined with Scene enums which are not extendable, which, btw, also explains the extensive use of switch statements, but I really have no idea if that hinders performance and how (where did you get that impression?). However, really need to look at the user-defined actions use-case as part of the proscene v2 design. In the mean time suggestions/patches are always welcome (for instance, this is how we're dealing with damping :) ).

I already answered your new issue (thanks for reporting them).

lllluj

Re: proscene camera damping

1 year ago

It is not exactly what is described in the topic you pointed out since the angle with the z axis can vary as well. Imagine a camera which is at the end of crane truck pointing towards the rotating base. "Free" rotation with the XY plane staying always horizontal.

It is implemented in the alpha version. The set of examples is completely broken. Look at anar->OBJECTS->StarGrid.

I am really interested in having user defined actions, since I have demanding users in terms of interaction... and I think it would also make the proscene camera a preferred choice for others. The only quick and dirty thing I would think of now is including in the enums some USER_DEFINED_ACTION1, etc to be of use when extending the InteractiveCameraFrame.

And I rechecked the if/else vs switch question and It actually seems that using switch is always faster, especially if your are using enum, on top of better readability. Really don't know where it came from. Should have checked before asking...

lllluj

Re: proscene camera damping

1 year ago

Another way of implementing user-defined mouse/keyboard actions would take the controlP5 way in which you can define your own callback function.

in an extension of Controller (Slider in this case)

addCallback(
   new CallbackListener() {
             public void controlEvent(CallbackEvent theEvent) {
                    // check something
if (theEvent.getAction()==ControlP5.ACTION_BROADCAST) {
// do something
}
}
}
)

this might be general and cleaner. You would then implement the default ones using the same syntax.

Not 100% sure it works in that case.

lllluj

Re: proscene camera damping

1 year ago

Hi,

I am trying to get what I call a right-handed world frame (useful for architects...) and I am not sure what the function

scene.setRightHanded()

does.

Basically I would like the XYZ frame to be standard (unlike in processing), that is if x is along thumb and y along index finger, z is along the major finger and pointing vertically upwards, all this using the right hand.

I suspect the function is for this, but I see no effect when setting it.

In my code I have the following function in my pre-draw function:

   // inverse frame of reference to get standard right handed XYZ world
    if (Scene.standardReferenceFrame)
        p5.scale(1,-1,1);

It does not have any influence any more. Are you resetting the matrix somewhere?

nakednous

Re: proscene camera damping

1 year ago

Hi,

Thanks for your suggestion about user-defined actions. Using a callback mechanism seems cleaner if someone wants to extend the implementation of a given action (as you did in the case of the ROTATION action), which in itself seems worth to be considered (btw, scene.addDrawHandler uses callback mechanism to animate scene objects). However, I'm not sure if it is also useful to add user defined actions, like DAMPING, i.e., in your example: has the controlP5.ACTION_BROADCAST being declared by the user?

When I first thought of scene.setRightHanded() I had in mind exactly what now you are needing. Then I focused on other features and decide to leave this one for a future release. I just forgot to remove that function ;) Coincidentally, however, as part of a future proscene-2 version, some days ago I was experimenting with the idea. I was thinking about it as a property attached to a frame which requires adding scaling to it (currently a Frame is defined only by a translation and a rotation), and thus a lot more of work since it affects many aspects of the library (KFIs, constraints,...). For this reason I doubt it will be part of proscene-1.2 which, apart from DAMPING, will be mainly only a port of the current functionality to P5-2.

In the mean time you could try something like this:

import processing.core.*;
import processing.opengl.PGraphicsOpenGL;
import remixlab.proscene.*;
@SuppressWarnings("serial")
public class BasicUse extends PApplet {
RightHandedScene scene;
public void setup() {
size(640, 360, P3D);
scene = new RightHandedScene(this);
}
public void draw() {
background(0);
fill(204, 102, 0);
box(20, 30, 50);
}
public class RightHandedScene extends Scene {
public RightHandedScene(PApplet p) {
this(p, (PGraphicsOpenGL) p.g);
}
public RightHandedScene(PApplet p, PGraphicsOpenGL renderer) {
this(p, renderer, 0, 0);
}
public RightHandedScene(PApplet p, PGraphicsOpenGL renderer, int x, int y) {
super(p, renderer, x, y);
}
@Override
protected void setPModelViewMatrix() {
super.setPModelViewMatrix();
renderer().scale(1, -1, 1);
}
}
}

and after that see if some other things would need some fine-tuning.

nakednous

Re: proscene camera damping

11 months ago

I just released a new version of proscene supporting damping and a new CAD camera profile. Please test it and let us know how it goes.

Do you manage to set right handed? If you do I can give it a try for a possible inclusion. Please comment.

nakednous

Re: proscene camera damping

10 months ago

I just released a new alpha (hopefully the last one) supporting scene.setLeftHanded() and scene.setRightHanded(). So basically, all the functionality you were looking for is there: CAD_CAM, damping, and handed ;)

Happy hacking!

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