Glass grenade

[Gorf]

...just that this forum allows images. It's a followup from a post in the list.

 

There are too many facets (it should have about 48 in total) and I miscalculated their regularity.

[D.Joseph Design]

Real grenades just blow up. But this, blowing glass all over the place, would really hurt if it detonates in your hand.

 

How do you plan to use this? Because, you know, people who live in stone houses don't throw glass rocks ... or grenades.

[Gorf]

Thanks for your reply, Daniel.

 

I just threw this together in half an hour to show the OP in this thread that it's possible to have a spline-bevelled glass surface without any internal surfaces to spoil its appearance.

 

I don't know why he wanted a glass grenade - I don't even know if he wanted any metal bits in it at all!

[Mr. Jaqe]

Cool, I like it. Well shaped and original.

[Biotron2000]

How about a wireframe? Maybe a quick tutorial? It looks very good.

[D.Joseph Design]

Oh. I thought this was from the same poster.

[JoshB]

Real grenades just blow up. But this, blowing glass all over the place, would really hurt if it detonates in your hand.

 

If it's a shrapnel grenade it divides those little square waffle shapes into shrapnel--flying pieces of sharp metal. Which looks to be the inspiration for the design. It is definitely an interesting concept--but, I want to see it work.

 

J

[Gorf]

Thanks for the replies.

 

@ Mr Jage - I can't see myself using this, but I'm toying with the idea of using it for a decanter or crystal whiskey tumbler.

 

@ Biotron: WF attached below. I still can't believe someone who's got "Master" status has asked me for a wireframe! I'll try my best to get a quick tutorial together.

 

@ Josh: I think glass just powders when subjected to really high pressure. Apart from shockwave, I think a glass grenade would be ineffective. I hope we get to see what Aldrich Quai Hoi (the OP I did this for) has planned for this "weapon".

[JoshB]

I think glass just powders when subjected to really high pressure. Apart from shockwave, I think a glass grenade would be ineffective. I hope we get to see what Aldrich Quai Hoi (the OP I did this for) has planned for this "weapon".

 

I think if they glass were thick enough and given the grooves it should work similar to the shrapnel grenade--breaking fast enough to avoid complete obliteration. Similar to this time a car window shattered from being off it's track. The glass just cracked and exploded outward in tiny pebble sized shards. To make it look believable will definitely be the hard part.

 

J

[Biotron2000]

Biotron: WF attached below. I still can't believe someone who's got "Master" status has asked me for a wireframe! I'll try my best to get a quick tutorial together.

 

Don't let that fool you...the designation is merely based upon the number of posts...one more and I think you'll be a "Master", too!

 

Looking at the wireframe, it looks like you lathed a shape, selected individual splines, then scaled them down to make the indentations. It looks great rendered. What settings did you use for index of refraction, translucency, etc.?

[Gorf]

Yep - I made the half cross-section with three lots of three CPs as per image:

(These will become the latitudinal troughs)

 

The reason for choosing 108 lathe sections is simple - I need three splines per longitudinal trough, and I want 12 panel sections. At a rough guess, I think that the space occupied between each of the troughs should be twice the width of the trough. So for every three trough splines I want six spacing splines. 12 x (3+6) = 108.

 

Lathe it, and you get a ridiculously complicated shape:

 

View it from the top, and use the lasso tool to get rid of the spacing splines:

 

Until you end up with this:

 

Then {Ctrl-click} a pint on each centre spline, and press {comma} to select the whole spline.

 

Turn the view without losing your selection, {Ctrl-click} then {comma} each of the three central latitudinal splines. Call this group "Inner ridge":

 

Scale the CPs that make up "Inner group" to 95%

 

If you want to be complete, you should go into top view, and scale these CPs back up from this:

so that they make a circle again.

 

Then you're ready to add all the other stuff to the model...

 

Apart from setting the diffuse colour to white (from black), and the refractive index to 1.05 (from 1) the materials are all identical to the way they are in the Hash-supplied library. I've attached the model itself in case it helps.

 

Total time, 35 minutes including screen capture and cropping in photoshop.

Grenade1.prj

[Biotron2000]

And now, you are a Master.

Great tutorial, too. Thanks!

[nf1nk]

Thats a really great grenade and a neat way to do that, (I have been doing similar technique except I have been twisting splines instead of deleting extra splines, it saves on crashing).

For the sake of details. I would like to point out that modern grenades do not have the cool grooves that your WWII/korean war grenade has. Even the frag grenade, has a smooth outside. Also the pin on a modern grenade is like a cotter pin (split in the middle), it still does have the ring.