[Insight-users] Re: 3DView : Z spacing
Luis Ibanez
luis.ibanez at kitware.com
Thu Jul 22 13:13:21 EDT 2004
Hi Alam,
Did you extracted the Mesh from a 3D Medical Image ?
If so, it is quite likely that your original image had
a larger spacing in Z than in X and Y, and it is likely
that you missed to take this different spacing into account
when you computed the coordinates of points in that surface.
Please double check your surface extraction algorithm in
order to verify if you are taking pixel spacing into account.
Regards,
Luis
-----------------------
Alam, Mohammed wrote:
>
> -----Original Message-----
> From: Luis Ibanez [mailto:luis.ibanez at kitware.com]
> Sent: Thursday, July 22, 2004 10:25 AM
> To: Alam, Mohammed
> Cc: Insight-users at itk.org
> Subject: Re: 3DView
>
>
> Hi Alam,
>
> We will be happy to help you figure
> out why your image is distorted...
>
>
> How about you tell us more about your
> code, the classes that you are using
> and...
>
>
> maybe you can be very nice with
> us and show us the code snippets that you
> are using for sending the image to FLTK :-)
>
>
>
> BTW, you may save a lot of time by just
> using the FLTK Viewer code available in
>
>
> InsightApplications/
> Auxiliary/FltkImageViewer
>
>
>
> Regards,
>
>
> Luis
>
>
>
> --------------------
> Alam, Mohammed wrote:
>
>
>>Hi Luis,
>>
>>I am trying to visualize my segmented object using FLTK. However my
>>segmented object seems to be compressed in the z-axis. I think the
>>aspect ratio of my window is disturbed.
>>
>>Could you let me know if that is the problem? And how can I fix it?
>>
>>Thanks
>>Alam
>>
>
>
>
>
>
> ------------------------------------------------------------------------
>
> //
> // "$Id: My3DView.cxx,v 1.1 2003/02/05 22:43:02 chenting Exp $"
> //
> // My3DView class implementation for the Fast Light Tool Kit (FLTK).
> //
> // Copyright 1998-2002 by Bill Spitzak and others.
> //
> // This library is free software; you can redistribute it and/or
> // modify it under the terms of the GNU Library General Public
> // License as published by the Free Software Foundation; either
> // version 2 of the License, or (at your option) any later version.
> //
> // This library is distributed in the hope that it will be useful,
> // but WITHOUT ANY WARRANTY; without even the implied warranty of
> // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> // Library General Public License for more details.
> //
> // You should have received a copy of the GNU Library General Public
> // License along with this library; if not, write to the Free Software
> // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
> // USA.
> //
> // Please report all bugs and problems to "fltk-bugs at fltk.org".
> //
>
> #include "My3DView.h"
> #include <math.h>
>
>
> #if HAVE_GL
> My3DView::My3DView(int x,int y,int w,int h,const char *l)
> : Fl_Gl_Window(x,y,w,h,l)
> #else
> My3DView::My3DView(int x,int y,int w,int h,const char *l)
> : Fl_Box(x,y,w,h,l)
> #endif /* HAVE_GL */
> {
> vAng = 0.0;
> hAng=0.0;
> size=1.0;
> xshift=0.0;
> yshift=0.0;
>
> #if !HAVE_GL
> label("OpenGL is required for this demo to operate.");
> align(FL_ALIGN_WRAP | FL_ALIGN_INSIDE);
> #endif /* !HAVE_GL */
> }
>
> #if HAVE_GL
> void My3DView::drawObject() {
> int k = 0;
> long num;
> double xmax, ymax, zmax, xmin, ymin, zmin, xmid, ymid, zmid;
> meshType::PointType node;
> const unsigned long *tp;
> meshType::PointType* node_pt;
> node_pt = &node;
>
> meshType::PointsContainerPointer points;
> meshType::PointsContainerIterator pointsit;
> meshType::CellsContainerPointer cells;
> meshType::CellsContainerIterator cellsit;
>
> points = m_mesh->GetPoints();
> pointsit = points->Begin();
> cells = m_mesh->GetCells();
> cellsit = cells->Begin();
>
> num = m_mesh->GetNumberOfPoints();
> xmax = ymax = zmax = 0.0;
> xmin = ymin = zmin = 10000.0;
> while ( k < num ) {
> node = pointsit.Value();
> if (node[0] > xmax) xmax = node[0];
> if (node[0] < xmin) xmin = node[0];
> if (node[1] > ymax) ymax = node[1];
> if (node[1] < ymin) ymin = node[1];
> if (node[2] > zmax) zmax = node[2];
> if (node[2] < zmin) zmin = node[2];
> k++;
> ++pointsit;
> }
>
> xmid = (xmax+xmin)*0.5;
> ymid = (ymax+ymin)*0.5;
> zmid = (zmax+zmin)*0.5;
>
> GLfloat light_ambient[] = {1.0, 1.0, 1.0, 0.5};
> GLfloat light_diffuse[] = {1.0, 1.0, 1.0, 1.0};
> GLfloat mat_specular[] = {1.0, 1.0, 1.0, 1.0};
> GLfloat mat_shininess[] = {50};
> GLfloat light_position[] = {1.0, 1.0, 1.0, 0.0};
>
> glShadeModel(GL_SMOOTH);
> glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
> glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
> glLightfv(GL_LIGHT0, GL_POSITION, light_position);
> glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
> glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
> glEnable(GL_LIGHTING);
> glEnable(GL_LIGHT0);
> glEnable(GL_DEPTH_TEST);
>
> glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
> k = 0;
> while( k < m_mesh->GetNumberOfCells()) {
> tp = cellsit.Value()->GetPointIds();
> glBegin(GL_POLYGON);
> m_meshnormals->GetPoint(tp[0], node_pt);
> glNormal3f(node[0], node[1], node[2]);
> m_mesh->GetPoint(tp[0], node_pt);
> glVertex3f(node[0]-xmid, node[1]-ymid, node[2]-zmid);
> m_meshnormals->GetPoint(tp[1], node_pt);
> glNormal3f(node[0], node[1], node[2]);
> m_mesh->GetPoint(tp[1], node_pt);
> glVertex3f(node[0]-xmid, node[1]-ymid, node[2]-zmid);
> m_meshnormals->GetPoint(tp[2], node_pt);
> glNormal3f(node[0], node[1], node[2]);
> m_mesh->GetPoint(tp[2], node_pt);
> glVertex3f(node[0]-xmid, node[1]-ymid, node[2]-zmid);
> glEnd();
>
> ++cellsit;
> k++;
> }
> }//drawObject
>
> void My3DView::setup() {
> glClearColor(0.0f, 0.0f, 0.0f, 1.0f );
>
> glEnable(GL_DEPTH_TEST);
> glShadeModel(GL_SMOOTH);
> glLineWidth(1.0f);
> }
>
> void My3DView::loadObject(meshPointer mesh) {
> m_mesh = mesh;
> }
>
> void My3DView::loadNormals(meshPointer meshnormals) {
> m_meshnormals = meshnormals;
> }
>
> void My3DView::draw() {
> if (!valid()) {
> glLoadIdentity();
> glViewport(0,0,w(),h());
> glMatrixMode(GL_MODELVIEW);
> glPushMatrix();
> glLoadIdentity();
> gluLookAt(0.0, 0.0, 256.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
> glMatrixMode(GL_PROJECTION);
> glPushMatrix();
> glLoadIdentity();
> gluPerspective(50.0, w()/(h()+0.0001), 5, 1000);
> glColor3f(1.0, 0.0, 0.0);
> glEnable(GL_DEPTH_TEST);
> // glOrtho(-10,10,-10,10,-20020,10000);
> glEnable(GL_BLEND);
> glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
> }
>
>
> glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
>
> glMatrixMode(GL_MODELVIEW);
> glPushMatrix();
> // glLoadIdentity();
> glTranslatef(xshift, yshift, 0);
> glRotatef(hAng,0,1,0); glRotatef(vAng,1,0,0);
> glScalef(float(size),float(size),float(size));
>
> if (m_mesh) drawObject();
>
> glPopMatrix();
> }
> #endif /* HAVE_GL */
>
> //
> // End of "$Id: My3DView.cxx,v 1.1 2003/02/05 22:43:02 chenting Exp $".
> //
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