Softbody port

BlitzMax Forums/BlitzMax Programming/Softbody port

VinceA (Posted 2007) [#1]

I did a port of a softbody simulation found here http://panoramix.ift.uni.wroc.pl/~MAQ/eng/ Can anybody tell me why the frame rate is so low SetGraphicsDriver GLMax2DDriver() Global SCRSIZE:Int = 7 Global NUMP:Int = 20 Global NUMS:Int = (NUMP+1) Global MASS:Float = 1.0 Global BALLRADIUS:Float = 0.516 Global KS:Float = 755.0 Global KD:Float = 35.0 Global GY:Float = -10.0 Global DT:Float = 0.005 Global FINAL_PRESSURE:Float = 45.0 Global Pressure:Float = 0 '/* Mouse */ Global windW:Int=380 Global windH:Int=380 Graphics windW,windH Print "h" Global MD:Int = 0 Global xMouse:Float Global yMouse:Float Global closest_i:Int=1 '/* Structure of the point */ Type CPoint2D Field x:Float = 0 Field y:Float = 0 Field vx:Float = 0 Field vy:Float = 0 Field fx:Float = 0 Field fy:Float = 0 End Type '/* Structure of the springs */ Type CSpring Field i:Int = 0 Field j:Int = 0 Field length:Float = 0 Field nx:Float = 0 Field ny:Float = 0 End Type '/* There we will keep an Object */ Global myPoints:CPoint2d[NUMP] Global mySprings:CSpring[NUMS] '/* Add New spring */4 Function AddSpring(Pii:Int , i:Int , j:Int ) mySprings[Pii] = New CSpring mySprings[Pii].i = i mySprings[Pii].j = j mySprings[Pii].length = Sqr((myPoints[ i ].x - myPoints[ j ].x)*(myPoints[ i ].x - myPoints[ j ].x).. + (myPoints[ i ].y - myPoints[ j ].y)*(myPoints[ i ].y - myPoints[ j ].y) ) End Function '/* Force Calculation Subroutine */ Function AccumulateForces() Local i:Int Local x1:Float Local x2:Float Local y1:Float Local y2:Float Local r12d:Float '// length of p1 - p2 vector Local vx12:Float '// vx1 - vx2 Local vy12:Float '// vy1 - vy2 Local f:Float '// hooke force value Local Fx:Float Local Fy:Float '// force vector Local volume:Float = 0 '// volume of the body Local pressurev:Float '// pressure force value '/* gravity */ For i = 0 To NUMP-1 myPoints[i].fx = 0 Local press:Float If (Pressure - FINAL_PRESSURE) <= 0 Then press = 0 Else press = 1 End If myPoints[i].fy = MASS * GY * press 'Print myPoints[i].fy '!! Note IF after IF !! '/* user clicked (mouse spring) */ If i=closest_i And MD = 1 Then '// closest point only '// If user clicked x1 = myPoints[ i ].x '// get points coords. y1 = myPoints[ i ].y x2 = xMouse y2 = yMouse r12d = Sqr ( (x1 - x2) *(x1 - x2) + (y1 - y2) * (y1 - y2) ) '// square '// root of the distance f = (r12d - 2.2) * 22 + (myPoints[ i ].vx * (x1 - x2) + myPoints[ i ].y * (y1 - y2)) * 54 / r12d '// calculate spring force Fx = ((x1 - x2) / r12d ) * f Fy = ((y1 - y2) / r12d ) * f '// accumulate force myPoints[i].fx :- Fx myPoints[i].fy :- Fy End If Next '/* spring force */ For i = 0 To NUMS-2 x1 = myPoints[ mySprings[i].i ].x y1 = myPoints[ mySprings[i].i ].y x2 = myPoints[ mySprings[i].j ].x y2 = myPoints[ mySprings[i].j ].y r12d = Sqr(( (x1 - x2) *(x1 - x2) ) + ( (y1 - y2) * (y1 - y2) )) '// square '// root of the distance If r12d > 0 Then vx12 = myPoints[ mySprings[i].i ].vx - myPoints[ mySprings[i].j ].vx vy12 = myPoints[ mySprings[i].i ].vy - myPoints[ mySprings[i].j ].vy f = ((r12d - mySprings[i].length) * KS) + (vx12 * (x1 - x2) + vy12 * (y1 - y2)) * KD / r12d Fx = ((x1 - x2) / r12d ) * f Fy = ((y1 - y2) / r12d ) * f myPoints[ mySprings[i].i ].fx :- Fx myPoints[ mySprings[i].i ].fy :- Fy myPoints[ mySprings[i].j ].fx :+ Fx myPoints[ mySprings[i].j ].fy :+ Fy End If '/* Calculate normal vectors To springs */ mySprings[i].nx = (y1 - y2) / r12d mySprings[i].ny = -(x1 - x2) / r12d Next '/* pressure force */ '/* Calculate Volume of the Ball (Gauss Theorem) */ For i = 0 To NUMS-2 x1 = myPoints[ mySprings[i].i ].x y1 = myPoints[ mySprings[i].i ].y x2 = myPoints[ mySprings[i].j ].x y2 = myPoints[ mySprings[i].j ].y r12d = Sqr( (x1 - x2) *(x1 - x2) + (y1 - y2) * (y1 - y2) ) '// square '// root of the distance volume :+ 0.5 * Abs(x1 - x2) * Abs(mySprings[i].nx) * (r12d) Next For i = 0 To NUMS-2 x1 = myPoints[ mySprings[i].i ].x y1 = myPoints[ mySprings[i].i ].y x2 = myPoints[ mySprings[i].j ].x y2 = myPoints[ mySprings[i].j ].y r12d = Sqr( (x1 - x2) *(x1 - x2) + (y1 - y2) * (y1 - y2) )' // square '// root of the distance pressurev = r12d * Pressure * (1.0/volume) myPoints[ mySprings[i].i ].fx :+ mySprings[ i ].nx * pressurev myPoints[ mySprings[i].i ].fy :+ mySprings[ i ].ny * pressurev myPoints[ mySprings[i].j ].fx :+ mySprings[ i ].nx * pressurev myPoints[ mySprings[i].j ].fy :+ mySprings[ i ].ny * pressurev Next End Function '/** ' * Euler Integrator ' */ Function IntegrateEuler() Local i:Int Local dry:Float Local drx:Float '// dr For Euler integration '/* Euler Integrator (second Newton's law) */ For i = 0 To NUMP-1 '/* x */ myPoints[i].vx = myPoints[i].vx + ( myPoints[i].fx / MASS )* DT drx = myPoints[i].vx * DT '/* Boundaries X */ If (myPoints[i].x + drx < -SCRSIZE) Then drx = -SCRSIZE - myPoints[ i ].x myPoints[i].vx = - 0.1 *myPoints[i].vx myPoints[i].vy = 0.95 *myPoints[i].vy '/* Boundaries X */ Else If(myPoints[i].x + drx > SCRSIZE) Then drx = SCRSIZE - myPoints[ i ].x myPoints[i].vx = - 0.1 *myPoints[i].vx myPoints[i].vy = 0.95 *myPoints[i].vy End If myPoints[i].x = myPoints[i].x + drx '/* y */ myPoints[i].vy = myPoints[i].vy + myPoints[i].fy * DT dry = myPoints[i].vy * DT '/* Boundaries Y */ If(myPoints[i].y + dry < -SCRSIZE) dry = -SCRSIZE - myPoints[ i ].y myPoints[i].vy = - 0.1 *myPoints[i].vy myPoints[i].vx = 0.95 *myPoints[i].vx '/* Boundaries Y */ Else If(myPoints[i].y + dry > SCRSIZE) dry = SCRSIZE - myPoints[ i ].y myPoints[i].vy = - 0.1 *myPoints[i].vy End If myPoints[i].y = myPoints[i].y + dry '/* fast chek If outside */ If(myPoints[i].x > SCRSIZE) Then myPoints[i].x = SCRSIZE If(myPoints[i].y > SCRSIZE) Then myPoints[i].y = SCRSIZE If(myPoints[i].x < -SCRSIZE) Then myPoints[i].x = -SCRSIZE If(myPoints[i].y < -SCRSIZE) Then myPoints[i].y = -SCRSIZE 'Print i Next End Function '/* Idle Function */ Function Idle() Motion() AccumulateForces() IntegrateEuler() '/** '* Update Pressure (pump an air into the ball) ' */ If(Pressure < FINAL_PRESSURE) Then Pressure :+ FINAL_PRESSURE/300.0 'FINAL_PRESSURE/100 ' Print"Pressure = "+Pressure End If 'glutPostRedisplay(); End Function '/* Reshape Window */ Function Reshape() 'glClearColor(0.4, 0.0, 0.0, 0.0); glMatrixMode (GL_PROJECTION) glLoadIdentity () gluOrtho2D(-SCRSIZE, SCRSIZE, -SCRSIZE, SCRSIZE) glMatrixMode (GL_MODELVIEW) glLoadIdentity() glDisable(GL_DEPTH_TEST) 'glViewport(0, 0, windW, windH) 'glMatrixMode(GL_PROJECTION) 'glLoadIdentity() 'gluOrtho2D(-SCRSIZE, SCRSIZE, -SCRSIZE, SCRSIZE) 'glMatrixMode(GL_MODELVIEW) End Function '/* Mouse Motion */ Function Motion() If MouseDown(1) Then If MD = 0 Then FindClosestPoint() MD = 1 Local mxf:Float = MouseX() Local myf:Float = MouseY() Local w:Float = windW Local h:Float = windH 'xMouse = MouseX() xMouse = SCRSIZE * 2.0 * (mxf / w - 0.5) yMouse = -SCRSIZE * 2.0 * (myf / h - 0.5) Else MD = 0 End If End Function '/* Visualization */ Function Draw() Local i:Int glClearColor(1,1,1,0) glClear(GL_COLOR_BUFFER_BIT) glBegin(GL_POLYGON) For i=0 To myPoints.length-1 glColor3f(0.8,0.4,0.4) glVertex2f(myPoints[i].x,myPoints[i].y) Next glEnd() If MD Then glColor3f(0,0,0) glBegin(GL_LINES) glVertex2f(xMouse,yMouse) glVertex2f(myPoints[closest_i].x,myPoints[closest_i].y) glEnd() End If Flip End Function '/* Find point in the model which is closest To mouse click point */ Function FindClosestPoint() Local dmin:Float Local mousepointd:Float Local i:Int '// find closest point Local disA = myPoints[closest_i].x - xMouse Local disB = myPoints[closest_i].y - yMouse dmin = Sqr((disA*disA) + (disB*disB)) For i=0 To NUMP-1 disA = myPoints[i].x - xMouse disB = myPoints[i].y - yMouse mousepointd = Sqr((disA*disA) + (disB*disB)) If mousepointd < dmin Then dmin = mousepointd closest_i = i End If Next End Function 'Function CreateBall Object (points & springs) */ Function CreateBall() Local angle:Float = 360.0/NUMP For Local i:Int = 0 To NUMP-1 ' !! Divide with Int !! myPoints[i] = New CPoint2d Local fi:Float = i Local h:Float =SCRSIZE myPoints[i].y = (BALLRADIUS) * Cos(fi*angle) + h/2 myPoints[i].x = (BALLRADIUS) * Sin(fi*angle) Next For i = 0 To NUMP-2 AddSpring(i,i,i+1) Next AddSpring(i,i,0) End Function Local mode,time CreateBall() While Not KeyHit( KEY_ESCAPE ) time=MilliSecs() Reshape() Draw() Idle() Idle() Idle() Idle() Idle() Idle() Wend

ImaginaryHuman (Posted 2007) [#2]

Seems okayish speed here, at least with the demo settings. Issue with your graphics card?

BlitzSupport (Posted 2007) [#3]

Dunno, it ran very well here, even in debug mode. (Nice job BTW.)

Ziltch (Posted 2007) [#4]

Works well here as well, even after increasing the poly count.

VinceA (Posted 2007) [#5]

Thanks everybody for taking the time. I think it must be a Open GL issue with my graphics card.. So now all I have to do is turn this in to a proper physics engine… ; )