FORUMS: list search recent posts

Burning sugar cubes

COW Forums : Autodesk Maya

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Hary
Burning sugar cubes
by
on Apr 19, 2005 at 9:23:01 am

Hi guys, Sean


Return to posts index

Sean Fennell
Re: Burning sugar cubes
on Apr 19, 2005 at 4:43:13 pm

Hi Hary,

granular surfaces are difficult to capture from a texturing point of view. They work kind of like volumes. It would help to see what you have so far to help improve on it. What you could try, is creating your cube with the sand texture on it. Then growing particles on surface and shading those with a similar shader (probably very small blobby particles with 0 threshold). That can give you some granularity to the surface. As for the burning, sugar does some interesting things. It carmelizes, which means it becomes half liquid half crystal. The effect is sort of a browning and slight liquification, then it burns. You might be able to use a ramp texture to animate the cube getting brownish on the corners first and then let the brown spread to the center of each face of the cube, while the corners get darker. There is some bubbling that happens too as the air is released forcefully from the heat of the flame. That usually happens on the top of the sugar cube. Best thing to do is burn a couple and see what happens (or watch that shot in From Hell when Johnny Depp puts the sugar in his absenth)


Return to posts index

Hary
Re: Burning sugar cubes
by
on Apr 19, 2005 at 4:55:17 pm

Sean, as usual I am delighted to see your reply, it makes a difference. Remember, I am in Prague, and this is the sole country in the EU (maybe apart from Spain) where Absinth is legal and easily consumed with burning sugar :) You need to come and visit! Anyway, this is for a company called Karamel, so I know about the melting and bubbling caramelization of the sugar. My biggest problem is the beginning, when the sugar cubes are white and grainy. I tried a displacement map, then simple bump maps and a layered texture, still getting it to look right. I'll send you some shots as I progress. Haven't worked with blobby surfaces and volumes yet, we'll see what happens! Thanks and later!


Return to posts index


Sean Fennell
Re: Burning sugar cubes
on Apr 19, 2005 at 5:40:26 pm

hey, you just might have to send me a bottle of absinth. Let me know if the particle thing works, its a shot in the dark.


Return to posts index

Steve Sayer
Re: Burning sugar cubes
on Apr 19, 2005 at 6:15:02 pm

[Hary] "My biggest problem is the beginning, when the sugar cubes are white and grainy. I tried a displacement map, then simple bump maps and a layered texture, still getting it to look right."

Hi, Hary. Sean is right, grainy surfaces are tough to capture. IMHO, the trick is that they need to glitter: highlights need to appear very hard and bright, and appear and disappear quickly with the slightest movement of the camera, object, or lightsource. These highlights are the result of reflections on tiny mirror-like facets of the sugar crystals.

My approach for surfaces like this is to create a material just for handling these highlights. You want to use a very grainy, sharply varying map for the surface normal to produce this behaviour in highlights--but you don't want that map affecting the diffuse shading at all.

You could try to fake it with one of Maya's very highly-contrasting, noisy textures, such as Mountain, or you could create an appropriate map in Photoshop using a Crystallize filter or something like that.

If you want to get more advanced, you can use a Shading Map shader to restrict the glittering highlights to just the most brightly-lit areas, and so on.

Here's a link to an old test I did with a similar type of surface: sequined fabric. This setup is much more complex than what I've described, and of course sequins and sugar crystals look quite different, but it should give you an idea of the kinds of 'glittering' effects that it is possible to achieve. You need DivX to view that first link; if you don't have it, try this QuickTime instead.

-Steve


Return to posts index

Sean Fennell
Re: Burning sugar cubes
on Apr 19, 2005 at 6:25:45 pm

If you want a really low tech, but tried and true method to creating sparkleys try this:

Instance hundreds of very small diamond shapes over the surface of your sugar cube. Shade them with a 100% transparent shader that has specularity turned all the way up. Use random rotation on the instances. What it gets you is small glints of specularity that always change with surface angle and light angle. It creates a complex look and is relatively easy to setup. May take a bit longer to render but it has depth and variation that is tricky to get with a shading network.


Return to posts index


bjohnston
Re: Burning sugar cubes
on May 6, 2005 at 6:28:58 pm

You could use a 3d fluid with a solid surface for the transition from sugar to burned. surface


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]