Beer glass scene creation
This course contains a little bit of everything with modeling, UVing, texturing and dynamics in Maya, as well as compositing multilayered EXR's in Photoshop.
# 1 07-03-2005 , 05:01 PM
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[Newbie] - Waterdrops on a "Coke-like" can...

Hi there! user added image
I'm working on a can just to explore the potentiality of MentalRay.

I've made the can from a revolved NURBS curve and kept it as a NURBS object, assigned a Blinn material for the metal and another Blinn for the printed label (including the Alpha channel) and then mixed togheter in a layered shader.
Say, I'm - almost - happy with the final result in MR's GlobalIllumination and FinalGather.

BUT...
Now I want the can to be more realistic and need to put some (ALOT, actually) waterdrops on it, just like they do in the ad-shots.
Well... How am I supposed to do that?
- PaintEffects?
- Shader based on transparencies and bump-mapping/displacement?
- "Particles"? (Don't have the first idea on how do they work) :/
- Ehrrr... build each drop one by one???

-________________ More hints here plz ;-) ________?


TNX in advance user added image

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# 2 08-03-2005 , 12:25 AM
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Particles would look the best. This is just off the top of my head, but you may wanna try
>select object and hit particles emit from object
>Turn the particle shapes into clouds s/w
>play movie frame till u get a good view of them
>shape them into drops

# 3 08-03-2005 , 04:04 PM
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there's a tutorial about this exact subject in this months 3d world magazine. I didn't read it but I did see it in there. See if you can get a hold of that magazine and it will tell you exactly how to do it.

But if it were me doing it I would do pretty much what umbrella said you wont be able to "shape" them as far as I know, but if they are small enough it shouldn't matter.

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# 4 08-03-2005 , 05:11 PM
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Instead of using the clouds s/w type, you could use particle geometry instancer to replace the particles with a modeled water droplet...


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# 5 08-03-2005 , 08:55 PM
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You can also raytrace refractions on particles by assigning a refraction grating, and turning the coke can "visible in refractions", and flipping on raytracing... maybe assign them a water-like shader.

You'll need to be a bit more careful with lighting when you raytrace, however.

# 6 09-03-2005 , 01:04 PM
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Okay...
First of all I wanna say TNX to everyone! user added image

I'm trying to combine the suggestion from Umbrella and kbrown ...
(Sorry Phopojijo, but I'm probably *too-much-noob* to understand what you suggested; although it sounds pretty interesting..)

I'm emitting particles from the can's surface and replacing particles with a pair of NURBS shaded spheres... It seems to work ;-)

<BUT>
Now the problems are:
- How may I kinda "constrain" the emitters not to trespass the can's shape more than a half of their respective diameter?
(Just the way they would act as if they were Nurbs object placed on a "MadeLive" can)

- Is there a way to set a "range" of random scaling for the emitters' size, in order to make 'em look more realistics?
(i.e: from "0.5" to "1.5" of their original size).

(If it all could be done without MELs, I'd be glad to know it ;-)p


I've got ALOT of other questions, actually, but I'll keep 'em for when those two problems are solved.
(If you don't mind me keepin' on asking, of course ;-)

TNX again!

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p.s.: Does anyone knows if I can buy a copy of "3d World Magazine" in Italy? Or someone who's got it could kindly post the tutorial Pure_Morning was talking about?


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# 7 12-03-2005 , 11:38 AM
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... are BUMPs allowed? user added image user added image

cià
ale - "making his drops by hands" :/


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# 8 12-03-2005 , 02:26 PM
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em I don't think bump would quite cut it, maybe displacement might do, but it would take longer to render and you'd have to paint the maps etc

I think it's better to go with a geometry and particles based solution

good suggestion though user added image

Alan


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# 9 12-03-2005 , 04:31 PM
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LOL user added image

As a matter of fact, I tried even "bump"mapping actually. But I didn't get any result. I wouldn't mind to paint the maps, so if U could tell me (step-by-step) how would you do with "displacement" I'd be glad to know ;-)

The "geometry and particles based solution" is nice, but I can't get a full control over it.
If I make it "rain" from above and raise the resillance of the can i can keep some drops stucked on it but I have alot of others floating around the object.
If I set the can as the emitter, once I choose "Surface", particles are emitted from the surface of the object (really?) and float ond the outside of it.
If I choose "Random", particles starts from inside of the object and get stucked (almost) at the surface but they even get alligned along UVs (I guess) giving a pretty unnatural look:
user added image
Apart from all this i still can't figure out how to make particles have a random size, or connect between them as real water would do... and so on... :/

Well, you see...
It's looking like I'm not actually working on a "can"; I'm probably working on a... "can't"! :p

Hey... What about having yourself a break and go out to buy that "3D World Magazine" with the tutorial you mentioned and post/send me even a quick scan of the tut-part?
Don't worry... I'll send you back a quick scan of the money you've spent! :p

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# 10 12-03-2005 , 06:23 PM
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This would definetly be a lot of work, but would give you control as to where the drops are. You could either project drop shaped curves onto the surface then build up the drops surface from them or make the can live and draw the curve directly on the can and do the same. Also with the can live you could try a liquid paint effect.



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# 11 13-03-2005 , 01:02 AM
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Is it for an animation, or single frame?

# 12 13-03-2005 , 03:27 PM
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Originally posted by mhcannon
This would definetly be a lot of work, but would give you control as to where the drops are. You could either project drop shaped curves onto the surface then build up the drops surface from them or make the can live and draw the curve directly on the can and do the same. Also with the can live you could try a liquid paint effect.

It's more or less what I'm doing right now... building Nurbs waterdrops and place 'em on the MadeLive can. I can surely get the total control over it, shaping and deforming each one of them, BUT...
A). Having a whole damn 3D Universe inside Maya, I feel a little stupid while I'm modeling each drop one by one...
B). What if I'd like to render a scene with, say, two or more copies of the same can? It would be ok if they'll have the same label; not that much if they'll have the same drops on their surface.

As for the "Liquid Paint Effect"; it sounds like a good hint but I don't have time to try it, now. (Expect me to be back late tomorrow asking "Where are them?!" ;-)

TNX

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# 13 13-03-2005 , 03:32 PM
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Originally posted by Phopojijo
Is it for an animation, or single frame?

It's just for practicing and learning purposes.
Having to choose one, I'd say a "single frame".
(Thou' you're making me willing to ask for a hint even for animation ;-)

TNX

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# 14 13-03-2005 , 08:35 PM
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The reason why I ask is because animations require dynamics, which is a pain in the ass (or manually keyframing each waterdrop that moves... and if the easier solution is labled as "a pain in the ass"... yea... you get the idea :b).

For single frames... I don't know how to do it in MAYA offhand, but you could just create (nurbs) spheres and manually place them all around the can. Make them poke ~1/2 way inside the can, varying for added effect... group them all, then assign them a shader.

I would recommend

https://www.highend3d.com/maya/shader...sort=file_name

About 5 entries down, Denfo_purewater. It also has the "raytracing' thing I was talking about... but you need to 1) Turn on raytracing in your render globals, and 2) Click "visible in refractions" on the coke can... not exactly sure where that is off hand... but someone else would.

It'll take more time to render, but it'll bend light like actual water.

# 15 15-03-2005 , 11:01 AM
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Originally posted by Phopojijo
[…]For single frames... I don't know how to do it in MAYA offhand, but you could just create (nurbs) spheres and manually place them all around the can. Make them poke ~1/2 way inside the can, varying for added effect... group them all, then assign them a shader.

Which is *exactly* what I'm doing... ;-)

BUT... but, but, but... I have a lot of "buts" about this...
You can read two of them in my answer above (to "mhcannon").
I've got another "but", here:
"What if water drops must be placed on a *transparent bottle*?"
(My intention was to make a can AND a bottle of beer).
Pokin'em 1/2 way inside the bottle would make the remaining 1/2 surface visible *inside* the bottle.
So, the best thing to do is probably to manually cut the shape of each drop 1/2 way from the start. "But" then I'll have a kinda 'planar surface' that wouldn't fit perfectly with the can's surface.

Dunno... I feel a little lost.
I have a strange (unsupported-by-knowledge) feeling that a "displacement" would be the best solution, for a static image. Thou' I don't have the first idea how to build waterdrops' displacements...

I would recommend
https://www.highend3d.com/maya/shader...sort=file_name
About 5 entries down, Denfo_purewater. It also has the "raytracing' thing I was talking about... but you need to 1) Turn on raytracing in your render globals, and 2) Click "visible in refractions" on the coke can... not exactly sure where that is off hand... but someone else would.
It'll take more time to render, but it'll bend light like actual water.

Yep, tnx ;-)
I've already d/led "Denfo_purewater" (I think I've been on each and every site which had the word "water" in it ;-)...
I even know how to handle the "raytracing" and "visible in refraction" things (or at least, I know that I can find them, somehow).
Still I preferred to use a simple Blinn with transparency set to "0", probably to stay focused on the shapes, rather than adding more troubles in the rendering step (which is already a "pain in the ass").

cià
ale-Keepin' on investigating

p.s: Damn it... Kurt! U teached us how to build a Dragon! What if in the Dragon's land it would rain, one day? :p


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