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submesh
03-30-2005, 12:51 AM
Hi.

I've been fiddeling around with the surface-editor trying to obtain a kind of effect where the object's surface properties appears or dissapears gradually from whichever angle. For an example: A car ad where you can see the translucent body of the car, and the car paint is laid down visually, combined with the attachment of vinyls (separate controls, like graphs, for each surface property).

SplineGod
03-30-2005, 01:24 AM
Use gradients with an input parameter such as incident angle. The blending mode can be set to alpha so that at various angles you can see to other texture layers.

submesh
03-30-2005, 02:26 AM
Incidence Angle, slope and such won't work because they are relative to the camera position. Just to make it clear: I want to animate the surface "falling down" on the object and cover it entirely, or moving from front-to-back on a car, which can be viewed by a camera from all kinds of angles.

Integrity
03-31-2005, 12:40 PM
Add a null to contol the position of the effect (the cutoff or graduall falloff position) and in the surface properties of your object use the Distance to Object parameter. I did this once to make a fetus gradually appear horizontally in it's own absolute position while the camera was circling around it. I forget the exact name of the parameters as I do not have Lightwave at my disposal right now but with a null and the gradient using that parameter you could control the alpha, transparency...an unlimited number of things in order to acheive your effect.

I hope this helps.

submesh
03-31-2005, 10:18 PM
Thanks.

In fact, this was the first thing I tried, but clearly I can't have done things right. Maby I forgot to use the alpha-property. I'll try it out as soon as I get a chance.

submesh
04-01-2005, 12:31 AM
Got it!! I did it right the first time, but forgot to use the Alpha-channel. Thanks for your advices :) Note: FPrime 1.01 does not support this kind of transparency/alpha-mixing properly. One of the reasons why I failed the first time.

prospector
04-01-2005, 02:44 AM
OK submesh..I'm jealous

you must be using LW on a cray supercomputer or something.
mine crashes at the 2 decimal point level (slow)
yours crashes at the 4 decimal point level (super fast)

I want what you got :D

submesh
04-01-2005, 03:42 AM
Haha! I got your point;) My processor run at about 2.5 ghz, about 9 billion calculations per second (can't remember where I've seen these figures tho). Suddenly, 0,0003 seems like an eternity compared to 0,0000000009 (based on a one-calculation-crash). Humm..think I'll stop here before someone discover my lack of knowledge, tie some rocks to my feet and throw me in the ocean:D Anyways, the real point is, it sometimes - after several hours of hard work - feels like the system just hit you in the face..very very fast.

submesh
04-01-2005, 05:59 AM
Ok, next challenge: To get the surface to drop down to the head of a human model, continue to the body and spread out to the arms, which is lifted 45 degrees upwards. As it is now, both head and arms recieves the surface-effect at the same time... Any suggestions? Should the arms be driven by seperate surface properties, and what about the borders that will appear in the joints?

Integrity
04-01-2005, 08:03 PM
I can think of two ways to do this besides creating a bunch of nulls a setting up a lot of gradients.

You can use a changed version of the UV morphing trick. I forget what they call it but it basically setting up a UV on one endomorph and than changing the shape of the model through the target in order to get a complicated UV mapping off. It based on how Lightwave calculates the order of all the morphs...you could try moving the arms down the base morph, apply a UV and add a texture that would control the alpha, then with another endomorph put the arms back up. Then just simply keep your arms-up morph in all the time, and if you move the texture from top to bottom in the original UV, it should spread out nicely and not just reveal vertically. I'm not totally sure about the technique but I know it works because I used it in order to create a shockwave moving over a bunch of complicated geometry.

The other was simply to create an animation of a circle or something getting bigger, and positioning it so as on part of the circle gets bigger the radius of curvature of it reveals your model in a spread kind of way like you said instead of the plain vertical. Or you can try making a vertex map where the last parts that will show up will be 100% and the first 0%, and then somehow animate a gradient using the Weight Map parameter...though I don't think you can animate the keys (it would be nice though).

I hope this helps.

SplineGod
04-01-2005, 09:06 PM
I would look at creating animated texture maps over a single UV map of the character. Its basically how I ended up creating this effect:
http://www.3dtrainingonline.com/anims/crawlers.avi

submesh
04-03-2005, 05:38 AM
Thanks for the tips, Integrity. Is it a tutorial out there which covers this technique? I'm not sure if I got everything you said.

Cool animation and a good idea, SplineGod.