surface of revolution

modelling with s.o.r's in kpovmodeler

some basic assumptions; you have kpovmodeler and pov-ray installed.
kpovmodeler can be found here at http://www.kpovmodeler.org/
and pov-ray's home url is here at http://www.povray.org/
kpovmodeler comes packaged with the kpovmodeler handbook in kde, useful for getting started and familiarising yourself with the the basic operations of kpovmodeler. you can access it by clicking on the help icon or find it at here
a good introduction on what sufaces of revolution are can be found in the online pov-ray documentation here

• launch kpovmodeler and delete the green box (unfortunately i don't think there is a way to modify the start-up screnn so that kpovmodeler opens without a green box)

• begin by inserting a declaration, selecting pigment, and solid colour with the values of 'rgbf 0.1098,0.58431,0.81961, 0.97 (note the f=filter value=0.97)

the html notation for that colour is #1C95D1,you can input this value into the colour select menu (which saves a lot of typing)

• insert a declaration for the finish, input the values;
phong, phong size 40, specular 0.6, roughness 0.5,reflection (min) 0.1, (max)0.4
•your object tree should look like this. tidy it up so that the declarations are underneath the globel settings, camera and light.

• insert the object surface of revolution as last child into the scene.

• opposite you can see the default settings, u=radius of the object, v=height, with the green arrows you can add or delete points

•ce1l row 1 is the base of the object, spline points do not have to increase diameter but each does have to have an increasing value in the v=height field.

• insert a pigment and link it to your declared colour, and the same for the finish

• do a quick render and your sor object should look like this

• i'm going to model a vase, add 8 more points in the sor menu giving each v value a higher numerical value than the previous and changing all radius values to 1, this makes the sor into a cylinder

• which doesn't look very exciting at all.

•zoom into the object in the left wire view frame (the scroll botton on the mouse allows you to zoom in and out) so that the object and all spline points are clearly visible

• move the mouse over the spline points and you will see that the pointer changes into a crosshair at every spline point. use the left click button and hold down to move each point to model the sor (or, obviously, change the values in the spline point menu).

• and here is the finished rendered image.

• for the mathematically inclined the on-line pov-ray manual at http://povray.org/documentation/view/3.6.1/286/ shows how to calculate s.o.r's

creating the inside of the vase

• up 'till now the sor is a solid object, you can click on 'open' in the sor's menu window but that option opens it on both ends, it won't have a base and the sides will have no thickness/depth, so we will create an interior for the vase. • the image is a bit dark so insert a plane into the scene (insert/infinate object/plane)and give it colour by inserting a pigment and then colour of your choice, i used #CF4F88. • your object tree should now look like this.
• check that your vase in on the plane (translate 0,-0.5,0) • insert a 'difference' into the scene (insert/constructive solid geometry/difference) • drag the sor into the difference • and duplicate (copy and paste) the sor object so you have two, and rename the second. • scale the second sor to 0.9,1.01,0.9, and translate 0,-0.49,0 • in the wire view window you can see that the inside object is slightly higher than the outside one, this is nescessary to preserve the base but cut open the top edge.
• finally, insert a union into the object tree and drag the 'differnce' into it as first child, this merges both sor's and you can treat it as a single object.
• and here, the rendered image

this page was created in quanta plus and the images created with the gimp

• launch kpovmodeler and delete the green box (unfortunately i don't think there is a way to modify the start-up screnn so that kpovmodeler opens without a green box) • begin by inserting a declaration, selecting pigment, and solid colour with the values of 'rgbf 0.1098,0.58431,0.81961, 0.97 (note the f=filter value=0.97) the html notation for that colour is #1C95D1,you can input this value into the colour select menu (which saves a lot of typing) • insert a declaration for the finish, input the values; phong, phong size 40, specular 0.6, roughness 0.5,reflection (min) 0.1, (max)0.4 •your object tree should look like this. tidy it up so that the declarations are underneath the globel settings, camera and light.
• insert the object surface of revolution as last child into the scene. • opposite you can see the default settings, u=radius of the object, v=height, with the green arrows you can add or delete points •ce1l row 1 is the base of the object, spline points do not have to increase diameter but each does have to have an increasing value in the v=height field. • insert a pigment and link it to your declared colour, and the same for the finish • do a quick render and your sor object should look like this
• i'm going to model a vase, add 8 more points in the sor menu giving each v value a higher numerical value than the previous and changing all radius values to 1, this makes the sor into a cylinder • which doesn't look very exciting at all.
•zoom into the object in the left wire view frame (the scroll botton on the mouse allows you to zoom in and out) so that the object and all spline points are clearly visible
• move the mouse over the spline points and you will see that the pointer changes into a crosshair at every spline point. use the left click button and hold down to move each point to model the sor (or, obviously, change the values in the spline point menu).
• and here is the finished rendered image. • for the mathematically inclined the on-line pov-ray manual at http://povray.org/documentation/view/3.6.1/286/ shows how to calculate s.o.r's