#1
|
|||
|
|||
rotating an object
Hi, I want to rotate an object (sphere) similar to the globe in google earth.
The sphere is mapped in front of the main view. With the use of the viz.pick() command I get the intersection position of the mouse pointer on the sphere (intersectionItem.point). The following code is running in a mouse button down callback function. While dragging the mouse over the sphere the new intersection position is callculated (curIntersectionItem.point) With this two points and the center of the sphere I get two direction vectors and the angle inbetween. The rotation of the sphere seems to work until it rolls. Then the mouse movement does not match to the rotation of the sphere any more! Is there a better way to achieve a stable rotation? While dragging in google earth the same part of the globe always stays under the mouse pointer. Code:
curIntersectionItem = calcUiIntersection() rotationMat = vizmat.Transform() rotationMat.makeVecRotVec(vizmat.VectorToPoint(sphere.getPosition(viz.ABS_GLOBAL),intersectionItem.point),vizmat.VectorToPoint(sphere.getPosition(viz.ABS_GLOBAL),curIntersectionItem.point)) spherePos = sphere.getPosition(viz.ABS_GLOBAL) sphereMat = sphere.getMatrix(viz.ABS_GLOBAL) sphereMat.setTrans(0,0,0) transformMat = vizmat.Transform() transformMat = rotationMat * sphereMat transformMat.setTrans(spherePos) sphere.setMatrix(transformMat,viz.ABS_GLOBAL) intersectionItem = curIntersectionItem |
#2
|
|||
|
|||
Interesting goal. I whipped up a bit of code that orbits the sphere by telling the sphere to "lookat" the intersection point, then rotating the sphere the initial offset amount.
The code is not quite right yet because sustained clicking on the same point rolls the sphere around that point. Maybe somebody knows whats wrong? Code:
import viz import vizmat import vizshape viz.go() viz.mouse.setOverride(viz.ON) node = vizshape.addSphere(pos=[0, 1.8, 3]) node.texture(viz.add('image2.jpg')) rotation = None def onGrab(): global rotation intersectionItem = viz.pick(1) if intersectionItem.valid: src_ori = vizmat.Quat(node.getQuat(viz.ABS_GLOBAL)) node.lookat(intersectionItem.point, viz.ABS_GLOBAL) dst_ori = vizmat.Quat(node.getQuat(viz.ABS_GLOBAL)) #D = O * S so O = D * 1/S rotation = src_ori * dst_ori.inverse() vizact.onmousedown(viz.MOUSEBUTTON_LEFT, onGrab) def moveSphere(): if rotation: intersectionItem = viz.pick(1) if intersectionItem.valid: node.lookat(intersectionItem.point) node.setQuat(rotation, viz.ABS_LOCAL) vizact.onupdate(viz.PRIORITY_DEFAULT, moveSphere) def endGrab(): global rotation rotation = None vizact.onmouseup(viz.MOUSEBUTTON_LEFT, endGrab)
__________________
Paul Elliott WorldViz LLC |
#3
|
|||
|
|||
Except for the slight roll, your code works fine. But here it comes: when I attach the sphere to the main view the rotation doesn't work any longer.
Code:
import viz import vizmat import vizshape viz.go() viz.mouse.setOverride(viz.ON) node = vizshape.addSphere(pos=[0, 1.8, 3]) node.texture(viz.add('image2.jpg')) viewLink = viz.link(viz.MainView,node) viewLink.preTrans([0,0,3]) rotation = None def onGrab(): global rotation intersectionItem = viz.pick(1) if intersectionItem.valid: src_ori = vizmat.Quat(node.getQuat(viz.ABS_GLOBAL)) node.lookat(intersectionItem.point, viz.ABS_GLOBAL) dst_ori = vizmat.Quat(node.getQuat(viz.ABS_GLOBAL)) #D = O * S so O = D * 1/S rotation = src_ori * dst_ori.inverse() vizact.onmousedown(viz.MOUSEBUTTON_LEFT, onGrab) def moveSphere(): if rotation: intersectionItem = viz.pick(1) if intersectionItem.valid: node.lookat(intersectionItem.point) node.setQuat(rotation, viz.ABS_LOCAL) vizact.onupdate(viz.PRIORITY_DEFAULT, moveSphere) def endGrab(): global rotation rotation = None vizact.onmouseup(viz.MOUSEBUTTON_LEFT, endGrab) |
#4
|
|||
|
|||
Righto. The link is overriding the rotation we are giving the sphere. To fix we tell the link to only operate on position
Code:
viewLink = viz.link(viz.MainView,node, mask=viz.LINK_POS)
__________________
Paul Elliott WorldViz LLC |
#5
|
|||
|
|||
Step by step I'm able to locate the source of the problem: I use the sphere in a hierarchical group order. The following code reproduces the strange behaviour of rotating.
Code:
import viz import vizmat import vizshape viz.go() viz.mouse.setOverride(viz.ON) root = viz.add(viz.GROUP, parent=viz.WORLD) root.setPosition([0,1.8,3],viz.REL_GLOBAL) node = vizshape.addSphere(pos=[0,0,0], parent=root) node.texture(viz.add('image2.jpg')) rotation = None def onGrab(): global rotation intersectionItem = viz.pick(1) if intersectionItem.valid: src_ori = vizmat.Quat(node.getQuat(viz.ABS_GLOBAL)) node.lookat(intersectionItem.point, viz.ABS_GLOBAL) dst_ori = vizmat.Quat(node.getQuat(viz.ABS_GLOBAL)) #D = O * S so O = D * 1/S rotation = src_ori * dst_ori.inverse() vizact.onmousedown(viz.MOUSEBUTTON_LEFT, onGrab) def moveSphere(): if rotation: intersectionItem = viz.pick(1) if intersectionItem.valid: node.lookat(intersectionItem.point) node.setQuat(rotation, viz.ABS_LOCAL) vizact.onupdate(viz.PRIORITY_DEFAULT, moveSphere) def endGrab(): global rotation rotation = None vizact.onmouseup(viz.MOUSEBUTTON_LEFT, endGrab) |
#6
|
|||
|
|||
Here's another way to do it.
Code:
from viz import * go() clearcolor(.8,.8,.8) vert = add('ball.wrl') vert.translate(0,1.8,2) xang = 0 yang = 0 INCREMENT = .5 mouse(OFF) restrictmouse(OFF) def mousemove(x,y): global xang,yang state = buttonstate() if state == MOUSEBUTTON_LEFT: xang = xang + x*INCREMENT yang = yang + y*INCREMENT vert.rotate(0,1,0,-x*INCREMENT,RELATIVE_WORLD) vert.rotate(1,0,0,y*INCREMENT,RELATIVE_WORLD) mousedata(RELATIVE,RELATIVE) callback(MOUSEMOVE_EVENT,mousemove) |
#7
|
|||
|
|||
Interesting... I shall dub thee Spinner Metaphor Method and place you in a file of honor.
__________________
Paul Elliott WorldViz LLC |
#8
|
|||
|
|||
Hi Gladsomebeast, the effect of slight roll results in the lookat call. The second argument is a optional roll value. The internal value of viz.ABS_GLOBAL is 4:
Code:
node.lookat(intersectionItem.point, 0, viz.ABS_GLOBAL) Code:
node.lookat(intersectionItem.point,viz.ABS_GLOBAL) Code:
node.lookat(intersectionItem.point,4) |
#9
|
|||
|
|||
Of course, of course, the roll parameter =) Thanks for sharing the fix.
__________________
Paul Elliott WorldViz LLC |
#10
|
|||
|
|||
Since spinning balls is so much fun,
Let's try spinning more than one. Code:
from viz import * go() clearcolor(.8,.8,.8) ball1 = add('ball.wrl') ball1.translate(.3,1.8,1.5) ball2 = add('ball.wrl') ball2.translate(-.3,1.8,1.5) balls = [] balls.append(ball1) balls.append(ball2) INCREMENT = .5 mouse(OFF) restrictmouse(OFF) def mousemove(x,y): object = pick() if viz.mouse.getState() == viz.MOUSEBUTTON_LEFT: mousedown = 1 else: mousedown = 0 if object in balls and mousedown == 1: object.rotate(0,1,0,-x*INCREMENT,RELATIVE_WORLD) object.rotate(1,0,0,y*INCREMENT,RELATIVE_WORLD) mousedata(RELATIVE,RELATIVE) callback(MOUSEMOVE_EVENT,mousemove) Or if you like the number three, Let's try to make them all agree. Code:
from viz import * go() clearcolor(.8,.8,.8) ball1 = add('ball.wrl') ball1.translate(0,2.1,2) ball2 = add('ball.wrl') ball2.translate(.4,1.5,2) ball3 = add('ball.wrl') ball3.translate(-.4,1.5,2) balls = [] balls.append(ball1) balls.append(ball2) balls.append(ball3) INCREMENT = .5 mouse(OFF) restrictmouse(OFF) def mousemove(x,y): object = pick() if viz.mouse.getState() == viz.MOUSEBUTTON_LEFT: mousedown = 1 else: mousedown = 0 if object in balls and mousedown == 1: for b in range(len(balls)): balls[b].rotate(0,1,0,-x*INCREMENT,RELATIVE_WORLD) balls[b].rotate(1,0,0,y*INCREMENT,RELATIVE_WORLD) mousedata(RELATIVE,RELATIVE) callback(MOUSEMOVE_EVENT,mousemove) And here's the one you want the most, Just like iPhone make it coast. Code:
from viz import * go() clearcolor(.8,.8,.8) ball1 = add('ball.wrl') ball1.translate(.3,1.8,1.5) ball2 = add('ball.wrl') ball2.translate(-.3,1.8,1.5) balls = [] balls.append(ball1) balls.append(ball2) increment = .5 COAST = 1 mx = 0 my = 0 object = [] spinning = 0 mouse(OFF) restrictmouse(OFF) def mousemove(x,y): global mx,my,object,spinning,increment if spinning == 0: object = pick() if mouse.getState() == MOUSEBUTTON_LEFT: object = pick() mousedown = 1 killtimer(COAST) spinning = 0 else: mousedown = 0 if object in balls and mousedown == 1: object.rotate(0,1,0,-x*increment,RELATIVE_WORLD) object.rotate(1,0,0,y*increment,RELATIVE_WORLD) mx = x my = y if mousedown == 1 and spinning == 0: increment = .5 spinning = 1 starttimer(COAST,.01,FOREVER) mousedata(RELATIVE,RELATIVE) callback(MOUSEMOVE_EVENT,mousemove) def onTimer(num): global spinning,mx,my,object,increment if num == COAST: object.rotate(0,1,0,-mx*increment,RELATIVE_WORLD) object.rotate(1,0,0,my*increment,RELATIVE_WORLD) increment = increment - .01 if abs(increment) < .01: spinning = 0 increment = .5 killtimer(COAST) viz.callback(viz.TIMER_EVENT,onTimer) |
#11
|
|||
|
|||
Spinning is fun
I do agree. But rotations be done, I'm going crazy.
__________________
Paul Elliott WorldViz LLC |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
retrieve Object names | Geoffrey | Vizard | 11 | 12-11-2009 04:26 AM |
reseting an object | durf | Vizard | 3 | 03-17-2009 11:48 PM |
Object rotating around world axis, not own axis | tacbob | Vizard | 1 | 02-15-2007 09:12 AM |
Child Object Rotation | paulgoldberg | Vizard | 5 | 09-05-2006 11:33 AM |
rotate to object | jargon | Vizard | 1 | 08-08-2005 12:20 PM |