1. Explain reflection and shear?
Reflection
• It is a mirror image of an object
• Rotating about 180 degree
• Flat object moving in the xy plane
• Reflection about y axis flips x coordinates
• Reflection point as pivot point is same as above
• To obtain the transformation matrix for reflection diagonal is y = -x
• Sequence
• Clockwise rotation by 45 degree
• Reflection about y axis
• Counter wise rotation by 45 degree
Shear
• Internal layer cause to slide over each other called shear
• Transforms coordinate position as X ‘= x + shx . y’ , Y’ =y
• Shift in the position of objects relative to shearing reference lines are equivalent to translations
2. Explain Liang Barsky line clipping
• Faster line clipper of the parametric equation of a line segment
• Line parallel to one of the clipping boundaries
• Line intersects the extension of boundary k
• If u1 > u2 line is outside the clipping window
• Else inside the clipping window
• Clipping is done using the reflection in the clip window
3. Explain Sutherland Hodgeman polygon clipping
• Clipping polygon which lies inside the clipping window
• Four possible cases
• If the first vertex is outside the window boundary and the second vertex inside
• If the first vertex is inside the window boundary and the second vertex outside
• If both are outside
• If both are inside
• Repeat the process of algorithm
• Convex polygon are correctly clipped using this clipping
• Concave and convex polygon are also used
4. Explain about clipping operations
• Clip a picture from either outside or inside a region known as clipping
• Also called as clipping algorithm
• The region against the object is known as clip window
• Clipping operations on different types of objects
• Point clipping
• Polygon clipping
• Area clipping
• Line clipping
• Curve clipping
• Text clipping
• Polygon and line clipping are the standard clipping components
Reflection
• It is a mirror image of an object
• Rotating about 180 degree
• Flat object moving in the xy plane
• Reflection about y axis flips x coordinates
• Reflection point as pivot point is same as above
• To obtain the transformation matrix for reflection diagonal is y = -x
• Sequence
• Clockwise rotation by 45 degree
• Reflection about y axis
• Counter wise rotation by 45 degree
Shear
• Internal layer cause to slide over each other called shear
• Transforms coordinate position as X ‘= x + shx . y’ , Y’ =y
• Shift in the position of objects relative to shearing reference lines are equivalent to translations
2. Explain Liang Barsky line clipping
• Faster line clipper of the parametric equation of a line segment
• Line parallel to one of the clipping boundaries
• Line intersects the extension of boundary k
• If u1 > u2 line is outside the clipping window
• Else inside the clipping window
• Clipping is done using the reflection in the clip window
3. Explain Sutherland Hodgeman polygon clipping
• Clipping polygon which lies inside the clipping window
• Four possible cases
• If the first vertex is outside the window boundary and the second vertex inside
• If the first vertex is inside the window boundary and the second vertex outside
• If both are outside
• If both are inside
• Repeat the process of algorithm
• Convex polygon are correctly clipped using this clipping
• Concave and convex polygon are also used
4. Explain about clipping operations
• Clip a picture from either outside or inside a region known as clipping
• Also called as clipping algorithm
• The region against the object is known as clip window
• Clipping operations on different types of objects
• Point clipping
• Polygon clipping
• Area clipping
• Line clipping
• Curve clipping
• Text clipping
• Polygon and line clipping are the standard clipping components
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