how do I spin an extrusion in Blender?

[angelize]

I found this once now I can't remember how I did it. I'm trying to create a vase from a profile shape I created in Xara. I have my shape converted to a mesh and I know I need to extrude and spin the shape to create my vase model. I just can't remember how to spin the extrusion. And I am going to tackle creating or (at least attempting to) glass, so any tips for doing that would be really helpful.

Thanks in advance!

[ODdOnLifeItself]

Hello Frances,

When you go to spin something, just remember that it defaults to spinning around the view axis. In other words, if you're spinning a vase, you make the profile from the front view, but spin it from above.

Just highlight your path in edit mode and then on the left toolbar, use Spin. It defaults to 9 steps and 90°, so just make it 360° of course and as many steps as you need to get the effect you want. You may also want to use less steps and use a SubSurf modifier as per my other recent post. (and the way I did it on my vases that I posted in Larry's scribble thread)

Hope this helps...

In the event that you have problems spinning the converted curve (sometimes spin is a bit iffy about having the correct path drawn), then you can just make a new object and follow the contour of the one that you imported.

Peace

James

[angelize]

Thank you, I knew I'd found it somewhere, and my vase spun perfectly. I'm calling it a night for now but hopefully tomorrow I'll try to make it look like clear glass. Any tips for that?

[ODdOnLifeItself]

Hello France,

You are welcome!

Re: Clear glass

There are many varieties of glass. The first question is if the vase refracts light or not. If so, then you'll (likely) have to play with the Index of Refraction to get it warping the light correctly. Though it might not be intuitive, the Index of Refraction drastically changes as small changes are made. You're basically telling it how much to warp the light and you can see that as you warp it more and more, those rays of bounced light end up in quite different places depending on this IOR. Small amounts are more like pane glass, while higher values can simulate almost any transparent or semi-transparent materials.

So...first, (after selecting the vase) turn on Transparency and select RayTrace (you can have glass without raytracing, but you can't have refraction without it). The Alpha value needs to be set to a very, very low value (otherwise the diffuse coloring of the glass is too prominent).

There are some other settings that you can play with, esp. the Fresnel value...but in general, the above is what is necessary to making realistic glass.

Hope this helps... one other little advice. Most glass not only refracts light, but also (on some small level!) reflects light. Because of this, your eyes expect to see some reflection of the environment. I would use it very sparingly (the reflection), but would include it. You can also use the Gloss amount (as per my other post about mirroring) so as to not have the reflections be so perfect that they're distracting.

Let me know how it comes along... I'm happy to help you find the perfect glass for your vase.

James

[angelize]

thanks for this. It may be a while before i get a chance to play with this, but I'm looking forward to it! I'll be sure to post my results

[ODdOnLifeItself]

Hello Frances,

I didn't like any reflection on this one, so went with only the specular highlights.

I made these to show how Index of Refraction alters the "glass vs crystal" element of the vase.

IndexOfRefraction.swf

Hope they help

James

[Soquili]

The Index of Refraction for some typical materials:
http://hyperphysics.phy-astr.gsu.edu...les/indrf.html

This link may be more usable by 3D modelers though : http://www.robinwood.com/Catalog/Tec...IndexList.html

[angelize]

That's really cool James.

I'm sure that list will come in handy when I get more into this.

Now another question: My vase has a seam from spinning it and I can't get rid of it. It didn't show up until I started smoothing the vase and recalculating doesn't get rid of it the ctrl+2 lessened it but not much how do I get rid of the seam?

[Soquili]

James can probably tell you right off the top of his head. I seem to remember something about removing duplicates immediately after making the spin.

[Soquili]

CTRL-V to bring up the vertex menu and Remove Doubles to remove the overlapping vertices.