Changes between Version 3 and Version 4 of CameraObjects

Timestamp:

04/24/12 12:32:34 (13 years ago)

Author:

Jonathan

Comment:

—

CameraObjects

@@ -48 +48 @@
 
 [[Image(rotating.gif, width=500)]]
+
+
+Clearly there are still some aliasing effects.  The routine that bins a cell into an image pixel is given below:
+{{{
+
+   SUBROUTINE BinCell(Camera, pos, dx, data, rho)
+      TYPE(CameraDef), POINTER :: Camera
+      REAL(KIND=qPREC) :: pos(3),xpos(3)
+      REAL(KIND=qPREC) :: dx, ddx, xlower(3)
+      REAL(KIND=qPREC), DIMENSION(:,:) :: data
+      REAL(KIND=qPREC) :: rho
+      INTEGER :: ipos(2), sample_res, i, j, k
+      xlower=pos-half*dx
+      sample_res=2d0*ceiling(camera%FOV(1)/camera%res / (dx/sqrt(sum(pos-Camera%pos)**2)))
+      ddx=dx/REAL(sample_res)
+      xlower=xlower-half*ddx
+      DO i=1,sample_res
+         xpos(1)=xlower(1)+ddx*i
+         DO j=1,sample_res
+            xpos(2)=xlower(2)+ddx*j
+            DO k=1,sample_res
+               xpos(3)=xlower(3)+ddx*k
+               ipos(1:2)=nint(GetPos(Camera, xpos)*shape(data))
+               IF (ALL(ipos(1:2) >= 1) .AND. ALL(ipos(1:2) <= shape(data))) THEN
+                  data(ipos(1),ipos(2))=data(ipos(1),ipos(2))+ rho*ddx**3
+               END IF
+            END DO
+         END DO
+      END DO
+   END SUBROUTINE BinCell
+}}}
+ We could in principal continue to raise the sample_res but it gets computationally expensive... A better approach would be to sample along each ray at some interval...  Then the sampling is pixel based instead of volume based - and should reduce the aliasing...