muskanmahajan37/modelgl

ModelGL

ModelGL

ModelGL

ModelGL.cpp of your modelview matrix project matModel.rotateZ(modelAngle[2]); matModel.rotateY(modelAngle[1]); matModel.rotateX(modelAngle[0]); matModel.translate(modelPosition[0], modelPosition[1], modelPosition[2]); matModelView = matView * matModel; glLoadMatrixf(matModelView.get()); if i change it to matModel.rotateZ(modelAngle[2]); matModel.rotateY(modelAngle[1]); matModel.rotateX(modelAngle[0]); matModelView = matView * matModel; matModelView.translate(modelPosition[0], modelPosition[1], modelPosition[2]); glLoadMatrixf(matModelView.get()); nothing happens, but if i make opengl do the translation part like this matModel.rotateZ(modelAngle[2]); matModel.rotateY(modelAngle[1]); matModel.rotateX(modelAngle[0]); matModelView = matView * matModel; glLoadMatrixf(matModelView.get()); glTranslatef(modelPosition[0], modelPosition[1], modelPosition[2])/* v' = Mt · Mr · v */ glTranslatef(...); glRotatef(...); glVertex3f(...);
matModelView (); / This creates a symmetric frustum. // It converts to 6 params (l, r, b, t, n, f) for glFrustum() // from given 4 params (fovy, aspect, near, far) void makeFrustum(double fovY, double aspectRatio, double front, double back) { const double DEG2RAD = 3.14159265 / 180;

double tangent = tan(fovY/2 * DEG2RAD);   // tangent of half fovY
double height = front * tangent;          // half height of near plane
double width = height * aspectRatio;      // half width of near plane

// params: left, right, bottom, top, near, far
glFrustum(-width, width, -height, height, front, back);

}// Note that the object will be translated first then rotated glRotatef(angle, 1, 0, 0); // rotate object angle degree around X-axis glTranslatef(x, y, z); // move object to (x, y, z) drawObject(); gluLookAt()glTranslatef() / This creates a symmetric frustum. // It converts to 6 params (l, r, b, t, n, f) for glFrustum() // from given 4 params (fovy, aspect, near, far) void makeFrustum(double fovY, double aspectRatio, double front, double back) { const double DEG2RAD = 3.14159265 / 180;

double tangent = tan(fovY/2 * DEG2RAD);   // tangent of half fovY
double height = front * tangent;          // half height of near plane
double width = height * aspectRatio;      // half width of near plane

// params: left, right, bottom, top, near, far
glFrustum(-width, width, -height, height, front, back);

} // rotate texture around X-axis glMatrixMode(GL_TEXTURE); glRotatef(angle, 1, 0, 0); ...glRotatef(), glTranslatef(), glScalef().

glPushMatrix();glRotatef(), glTranslatef(), glScalef().

// set view matrix for camera transform glLoadMatrixf(matrixView.get());

// draw the grid at origin before model transform drawGrid();

// set modelview matrix for both model and view transform // It transforms from object space to eye space. glLoadMatrixf(matrixModelView.get());

// draw a teapot after both view and model transforms drawTeapot();

glPopMatrix(); ... glPushMatrix

...height() glPushMatrix();

// initialze ModelView matrix glLoadIdentity();

// First, transform the camera (viewing matrix) from world space to eye space // Notice translation and heading values are negated, // because we move the whole scene with the inverse of camera transform // ORDER: translation -> roll -> heading -> pitch glRotatef(cameraAngle[2], 0, 0, 1); // roll glRotatef(-cameraAngle[1], 0, 1, 0); // heading glRotatef(cameraAngle[0], 1, 0, 0); // pitch glTranslatef(-cameraPosition[0], -cameraPosition[1], -cameraPosition[2]);

// draw the grid at origin before model transform drawGrid();

// transform the object (model matrix) // The result of GL_MODELVIEW matrix will be: // ModelView_M = View_M * Model_M // ORDER: rotZ -> rotY -> rotX -> translation glTranslatef(modelPosition[0], modelPosition[1], modelPosition[2]); glRotatef(modelAngle[0], 1, 0, 0); glRotatef(modelAngle[1], 0, 1, 0); glRotatef(modelAngle[2], 0, 0, 1);

// draw a teapot with model and view transform together drawTeapot();

glPopMatrix(); ...

/////////////////////////////////////////////////////////////////////////////// // return a perspective frustum with 6 params similar to glFrustum() // (left, right, bottom, top, near, far) /////////////////////////////////////////////////////////////////////////////// Matrix4 ModelGL::setFrustum(float l, float r, float b, float t, float n, float f) { Matrix4 matrix; matrix[0] = 2 * n / (r - l); matrix[5] = 2 * n / (t - b); matrix[8] = (r + l) / (r - l); matrix[9] = (t + b) / (t - b); matrix[10] = -(f + n) / (f - n); matrix[11] = -1; matrix[14] = -(2 * f * n) / (f - n); matrix[15] = 0; return matrix; }

/////////////////////////////////////////////////////////////////////////////// // return a symmetric perspective frustum with 4 params similar to // gluPerspective() (vertical field of view, aspect ratio, near, far) /////////////////////////////////////////////////////////////////////////////// Matrix4 ModelGL::setFrustum(float fovY, float aspectRatio, float front, float back) { float tangent = tanf(fovY/2 * DEG2RAD); // tangent of half fovY float height = front * tangent; // half height of near plane float width = height * aspectRatio; // half width of near plane

// params: left, right, bottom, top, near, far
return setFrustum(-width, width, -height, height, front, back);

}glRotatef() glTranslatef() glScalef() /////////////////////////////////////////////////////////////////////////////// // set a orthographic frustum with 6 params similar to glOrtho() // (left, right, bottom, top, near, far) /////////////////////////////////////////////////////////////////////////////// Matrix4 ModelGL::setOrthoFrustum(float l, float r, float b, float t, float n, float f) { (m0, m1, m2), (m4, m5, m6) and (m8, m9, m10)(m12, m13, m14) Matrix4 matrix; matrix[0] = 2 / (r - l); matrix[5] = 2 / (t - b); matrix[10] = -2 / (f - n); matrix[12] = -(r + l) / (r - l); matrix[13] = -(t + b) / (t - b); matrix[14] = -(f + n) / (f - n); return matrix; } ...

// how to pass projection matrx to OpenGL Matrix4 projectionMatrix = setFrustum(l, r, b, t, n, f); glMatrixMode(GL_PROJECTION); glLoadMatrixf(matrixProjection.get()); (m0, m1, m2) : +X axis, left vector, (1, 0, 0) by default (m4, m5, m6) : +Y axis, up vector, (0, 1, 0) by default (m8, m9, m10) : +Z axis, forward vector, (0, 0, 1) by default

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