PDA

View Full Version : How to fade the opacity of an object?


vintagetone
07-21-2006, 05:22 PM
I have planes with images for opacity (transparency) and diffuse, but I need to fade the whole object out. In Max there was a way to do that, the attributes of the object had an opacity setting that could be animated appart from the material opacity that was mapped to the object.

Any one know of a similar way I could do that in Maya? I need these objects to fade out of the way as the camera moves behind them.

Thank you

Digit
07-21-2006, 05:28 PM
You can do exactly the same thing in Maya. Just right click on the transparancy slider for the sahder in the attribute editor and set a key from the menu that appears. Then do it again later on the time line. The shader will have a curve for it in the graph editor now.

vintagetone
07-21-2006, 09:33 PM
Thank you for replying to my question.

Right, but there is a bitmap in the transparancy slot that is driving it.

One suggestion I got was use a blender for the transparency and animate between the initial bitmap to an all white one for when I need the object to dissapear. I'll give that a try.

Emil3d
07-22-2006, 05:57 AM
In the Color Balance section of the node (tab) for your "bitmap", reduce the Alpha Gain if you connected the .outTransparency to .transparency, or change the Color Offset to white if you connected the .outColor to .transparency.

Edit: This is a solution for the problem described in the vintagetone’s message above. Later I read the whole thread and realized that it is not about transparency but fading an object and gave a suggestion in my next message in this thread.

DrEvilBear
07-26-2006, 05:16 PM
or go into your graph editor, and animate the 'visibility' for your plane, as this is completely seperate from the objects ahder attributes...

best of luck

leif3d
07-26-2006, 08:22 PM
The problem of animating the visibility is that it's only on or off....no gray values....you can't have a smooth transition for disappearance of an object, unless you animate the shader's transparency...but then that would affect every object associated with that shader group...

A while ago I had a similar problem...we fixed it with a hidden node called "smoothstep"...I remember connecting this to the visibility and animating a gradation somehow....too bad I don't have my notes anymore...

If you find a solution let us know...meanwhile I'll ask a couple of guys to figure it out.

swardson
07-26-2006, 08:49 PM
you can accomplish that with utility nodes in your shader tree

use colorBlend or multiplyDivide node to get a value to change the bitmap from itself to white.

to do it on an object level use a switch utility to change how each object recieves the shader information.

jaygarrison3d
07-26-2006, 10:11 PM
If you just fade out the transparency on your materials, you'll end up with a glassy object because it will retain your spec and reflection settings. You could run each of those materials into a layered shader, reapply your layered shaders to your object, then fade out it's alpha with in the layered shader.

Honestly, the easiest way would be to comp it. Just render out your fading objects in there own passes and fade them out in after effects or a similar app.

Hope some of this helps.

Digit
07-27-2006, 05:53 AM
Honestly, the easiest way would be to comp it. Just render out your fading objects in there own passes and fade them out in after effects or a similar app.

Hope some of this helps.

I agree with this but I also have to say that this is a good example of how maya can be such a pain in the ass sometimes. It should be such an easy thing to do really.

Emil3d
07-27-2006, 06:08 PM
Fading is purely 2D compositing effect and naturally it is easiest to do in a dedicated 2D program.
In version 7, Maya introduced some very basic compositing in Render View renderer when used with render layers.

To compose a fading effect in Render view, you have to put all surfaces of the fading object in a render layer and then Create Layer Override and animate the Matte Opacity of all materials for those surfaces.
To see the compositing effect you have to have object/s behind the fading object that are added in a layer below, and make sure that Render All Layers is checked in the Render View’s Render menu.

vancliff
07-28-2006, 01:12 AM
There is a workaround of it. I have put a maya 7 file so you can check by yourself.

leif3d
07-28-2006, 04:22 AM
Thanks for your help vancliff:)
But what's happening is that we are trying to figure out a solution to a per object transparency dissolve...not a shader one...I haven't been able to find an easy solution to this...well I guess in Maya nothing is very easy.:shrug:

Emil3d
07-28-2006, 05:43 AM
vancliff, I checked your file and all it does is animated ramp plugged into the transparency, which I don’t think has anything to do with what I understand is a fading effect. If you have used a video camera you may have noticed the fading effect that all of them have now for many years. What is does is turns gradually the image into complete black, white, or gray color. In compositing this is usually when one image gradually disappears (fades) to reveal another image or the background behind the fading image. This has nothing to do with transparency where during the disappearing everything gets transparent so that one can see the guts let's say of a 3D character like eye’s spheres, teeth, tong, and the opposite side of it. Of course if you object is open geometry without overlaps from the viewing angle, animating the transparency and other attributes can have the same effect as fading.

kyleb2112
07-29-2006, 08:30 AM
I've asked the same question before on this board perviously and got no responses. I had to do all my fades in post which made it much more difficult to do the sound sync. It's a shame that something as simple as object visibility isn't animatable as a float rather than just a boolean.

samel
08-04-2006, 01:54 PM
yep, i have the same problem..
this is just ridiculous..

i have maybe 10 different objects and i want them to fade in and out at different
times and they all use the same shader..no option but duplicating the shader ten times then
..thanks a bunch alias..

//s

Emil3d
08-04-2006, 06:07 PM
In my opinion people who expect a 2D fading effect in Maya to be available and easy thing are lacking basic understanding of the differences between 2D and 3D.

As I said earlier, fading is purely a 2D effect that makes one image reveals (blend into) another. Maya creates images when it renders a scene. It is not designed to do much after that point although as I said already some very basic compositing capabilities are available in Render View with Maya 7 where you can check the compositing effect.

Fading is such easy and trivial task to do in any 2D compositing program. And a compositing program has the same or better video/audio sync capabilities than Maya.

Maya is already pretty much Jack of all trades program and it is amazing how much further users want to push that limit. I won’t be surprises if somebody complains that there is no spell checking available in the viewports.:)

Some programs like XSI come bundled with compositors but the workflow is basically the same as using a third party compositing software.

almux
08-04-2006, 08:09 PM
In my opinion people who expect a 2D fading effect in Maya to be available and easy thing are lacking basic understanding of the differences between 2D and 3D.

As I said earlier, fading is purely a 2D effect that makes one image reveals (blend into) another. Maya creates images when it renders a scene. It is not designed to do much after that point although as I said already some very basic compositing capabilities are available in Render View with Maya 7 where you can check the compositing effect.

Fading is such easy and trivial task to do in any 2D compositing program. And a compositing program has the same or better video/audio sync capabilities than Maya.

Maya is already pretty much Jack of all trades program and it is amazing how much further users want to push that limit. I won’t be surprises if somebody complains that there is no spell checking available in the viewports.:)

Some programs like XSI come bundled with compositors but the workflow is basically the same as using a third party compositing software.
If I reformulate your quote, it seams evident to render the scene with caracter - with no caracter - and caracter alone separately and do that fading in FinalCut, AfterEffects, Shake or whatever compositing app (within or without some gradated alpha) ... right?

Emil3d
08-04-2006, 09:27 PM
almux, fading a character out of a scene would require just 2 layers a character with an alpha mask in the top layer and the rest of the scene in the layer below. In the compositing program just animate the transparency of the top layer (character) for certain number of frames and all programs can preview the result in real time and you will have the flexibility to quickly check different durations for the fading transition and even graph the fading against the time.

In general everybody uses a compositor to assemble animation produced with a 3D program anyway. If you have a scene where only the character moves and nothing else you don’t want to render the same background for each frame again and again. You just render one frame for the background and in the compositor you just tell it how long to repeat it. These are just a few of many many other benefits to render scenes in separate layers (passes)

samel
08-06-2006, 11:12 AM
In my opinion people who expect a 2D fading effect in Maya to be available and easy thing are lacking basic understanding of the differences between 2D and 3D.

these kind of statements is what's stagnating the industry..
sorry, but thats about the stupidest thing i've ever heard.

//s

leif3d
08-06-2006, 01:17 PM
these kind of statements is what's stagnating the industry..
sorry, but thats about the stupidest thing i've ever heard.

//s

Even though I don't agree with you calling someones opinion "stupid":shrug: , I agree that features like these should be implemented somehow, because Maya is also being used a lot in the Motion Graphics field now a days as opposed to only in big animation productions...for Example, I sometimes have to do jobs from Design stage to Post-production (TV station) and features like per-object visibility in Maya would speed up my workflow considerably...I sometimes have to render more than 15 layers for projects to manipulate them in post...don't get me wrong...I'm used to it and I generally like to have that control in post anyhow...but having it within Maya for trivial tasks would be nice.

Catzzzpaws
08-06-2006, 02:08 PM
I had exactly the same thing to accomplish - (in my case fading in and out furniture in an architectural visualization) - and had to solve it in post. The main reason for that were the enormously longer rendering times when fading out transparency, reflectivity and specularity. Raytracing almost killed me - and having transparent/semi-transparent shadows didn't help either with the effect.

Emil3d
08-06-2006, 04:50 PM
these kind of statements is what's stagnating the industry..
sorry, but thats about the stupidest thing i've ever heard.//sSamel, I stand by my statement and I believe that regarding this, you really don’t understand the difference between 3D and 2D. I’ll try to help you in case you are interested.

I’ll give an example. If you have access to Photoshop or other compositing programs like After Effects that have layers, just create 2 layers with different images in each layer. Then drag the opacity slider of the top layer and you will see the final result in real time (no rendering required) even for images with much higher resolution than those required for motion pictures. This is possible because there are relatively very little calculations required for this process. The color of each pixel is described by just 3 numbers (for R, G, and B), and all the program has to do is calculate the blend of these 3 numbers with the 3 numbers of the pixel below from the other layer.

In 3D, the calculations involved in rendering, which is producing pixels (images) form a description of 3D geometry, is gigantically huge comparing to the calculations involved in blending pixels in 2D. That’s why the word rendering was introduced in the 3D world which for me in other words means “waiting time for those calculations to complete” :)

Now let’s suppose that in addition to the regular rendering calculations, the renderer has to calculate a fading effect. For example you have a character with clothes, hair, accessories, may be carrying a gun or something else, may be a robe blown by the wind, and etc.
First, to fade all this consistently the program has to recognize what is the background and what is not and this is going to be a challenge for characters moving in front from behind objects or moving through them, not to mention cases like wearing waving cloths or flags. Then the program must mask out all overlapping geometry of the fading surfaces (you don’t want to see the guts or the other side of your character – like the buttocks through the front during the fading). Imagine the calculations involved in all this comparing simple pixel blending. In addition to that the program has to animate each contributing attribute like secularity, reflections, even transparency (how about if your character holds fading transparent objects like wine glasses and bottles), also the light’s intensities may need to be dimmed gradually only for the fading objects too. These are just some of the things that may need to be involved for producing a fading effect using 3D controls.
Not only tremendous calculations but this also will require much more user involvement than just dragging a slider in a 2D program. Event if technically possible implementing all this won’t make any sense. What makes sense it to make the fading in a 2D environment and if you want that in Maya, they have to extend the program by including a 2D compositor like in XSI. That may eventually make some of the controls integrated in the 3D environment at a stage before rendering but the actual effect will be always produced at a post production stage.
Basically, at the end no matter when and where you spend the time for controlling the fading, it will always require similar amount of user involvement (clicks, mousing, buttons, windows) as to open your rendered frames in a third party program like Photoshop or After Effects. And I don’t thing incorporating a compositor in Maya will come free, without increasing its price, especially if it has to rival the popular programs out there.

I hope this helps.

samel
08-07-2006, 09:20 AM
Samel, I stand by my statement and I believe that regarding this, you really don’t understand the difference between 3D and 2D. I’ll try to help you in case you are interested.

i have a very thorough understanding about how this works so stop assuming.
that is besides the point though.
if you step out of the box with me for a while. what i want is something
like a per-object texture override. very much like the particle-attributes.
rgb and opacity..just some automation instead of having to
assign a new shader to each object.

as for all the heavy calculation you anticipate being involved with rendering
opacity.. as said before. people do motion graphics with maya aswell
and that generally doesnt mean full-character/major-scene with tons of complex animated
objects layered in front of eachother but often what you need are a couple of
design elements to fly around and fade in and out independently.
but even so, if one wants to set per-object opacity right through the scene, one should have the ability to, no matter if it takes a week to calculate (i seriously doubt that thuogh).

sorry for flaming but i get p**d off whit nerd-talk about what you can and cant do..
it's like arguing about which is best, max or maya..just drop it! you should be able to do anything you want with whatever tool you fancy.

//s

Emil3d
08-07-2006, 12:23 PM
i have a very thorough understanding about how this works so stop assuming.Well sorry if this offends you, but this is internet and in most cases people don’t know each other and I think assuming lack of knowledge is more helpful than the opposite when communicating. I’ve never suffered or feel offended if somebody is telling me things that I already know. However there are a lot of cases where I have not understood or find useful communications where the other side assumes that I know more than I really do.if you step out of the box with me for a while. what i want is something like a per-object texture override. very much like the particle-attributes.
rgb and opacity..just some automation instead of having to
assign a new shader to each object.This is already in Maya and is fully automated as much as I can imagine. Select the objects you want and in the render layers, click “Create new layer and assign selected objects” button. Then from the render shelf click on any shader and that’s it – your selected objects have a shader override in that layer only without affecting their shader in the master layer.
The problem is that this is not going to give you as easy, fast, and efficient path to a fading effect as if you do it in a 2D environment for the reasons I explained in my previous message.

See my point is, when something is difficult I can’t just request whishing that somebody, somehow, in some way should try to see how it can be done easier if I myself can’t even imagine the easy steps. And that’s what I don’t see from you and those who request a fading effect in Maya. Really how do you imagine it? Exactly what user actions you want and what effect these actions will have on what? And how what you imagine will be easer, faster, and more efficient than the current solution to render layers, open the rendered frames in a compositor and animate the opacity there?

leif3d
08-07-2006, 08:28 PM
Well sorry if this offends you, but this is internet and in most cases people don’t know each other and I think assuming lack of knowledge is more helpful than the opposite when communicating. I’ve never suffered or feel offended if somebody is telling me things that I already know. However there are a lot of cases where I have not understood or find useful communications where the other side assumes that I know more than I really do.This is already in Maya and is fully automated as much as I can imagine. Select the objects you want and in the render layers, click “Create new layer and assign selected objects” button. Then from the render shelf click on any shader and that’s it – your selected objects have a shader override in that layer only without affecting their shader in the master layer.
The problem is that this is not going to give you as easy, fast, and efficient path to a fading effect as if you do it in a 2D environment for the reasons I explained in my previous message.

See my point is, when something is difficult I can’t just request whishing that somebody, somehow, in some way should try to see how it can be done easier if I myself can’t even imagine the easy steps. And that’s what I don’t see from you and those who request a fading effect in Maya. Really how do you imagine it? Exactly what user actions you want and what effect these actions will have on what? And how what you imagine will be easer, faster, and more efficient than the current solution to render layers, open the rendered frames in a compositor and animate the opacity there?


I have an easy step...

Visibility with a Float value instead of an Integer:wise: this should give you a curve...then you get a disolving object.
...my request is not evaluating what's posible or not posible...it's just a request...maybe it can't be done...maybe it can...I'm just saying that it would be cool to have it.

Emil3d
08-07-2006, 09:39 PM
I have an easy step...

Visibility with a Float value instead of an Integer:wise: this should give you a curve...then you get a disolving object.
...my request is not evaluating what's posible or not posible...it's just a request...maybe it can't be done...maybe it can...I'm just saying that it would be cool to have it. And how that float slider will be cooler, or require less effort from the slider that is already in the compositing programs like Affter Effects?
Don’t tell me that you don’t want to preview and adjust the fading effects in a compositor with the complete beauty of the final rendering but instead you prefer the "cool" preview it in the Maya viewport with your video card displaying the fading with a cheep x-ray transparency animation.

If you want all this in order to avoid using a compositing program you will be limited to rendering as .AVI which is something practiced only by not serious and non professional 3D users.
Then if you render a sequence, you will need a descent compositing program anyway to at least compile and encode your movie.

And if you want fading in Maya in order to avoid layers and complain from them being a burden, it is the same to hear from a Photoshop user who hates layers because they are hard and waste of time and he/she would like to never use them and works only on the flattend backgound canvas.

leif3d
08-08-2006, 01:09 AM
And how that float slider will be cooler, or require less effort from the slider that is already in the compositing programs like Affter Effects?
Don’t tell me that you don’t want to preview and adjust the fading effects in a compositor with the complete beauty of the final rendering but instead you prefer the "cool" preview it in the Maya viewport with your video card displaying the fading with a cheep x-ray transparency animation.

If you want all this in order to avoid using a compositing program you will be limited to rendering as .AVI which is something practiced only by not serious and non professional 3D users.
Then if you render a sequence, you will need a descent compositing program anyway to at least compile and encode your movie.

And if you want fading in Maya in order to avoid layers and complain from them being a burden, it is the same to hear from a Photoshop user who hates layers because they are hard and waste of time and he/she would like to never use them and works only on the flattend backgound canvas.

Excuse me for saying this Emil3d, but you seem like you're trying to defend a point instead of understanding other opinions.

I said pretty clearly that I like to have control over my layers in after effects...but I don't want to render Layers if I don't have to for simple tasks...for example, a logo that comes in the frame in 8 pieces at different times while dissolving...I have to generally render out 1 Layer of RGB and 8 layers of Mattes because they intersect each other...that's 9 Layers...for a stupid Flying Logo? I could just animate the Visibility gradually within Maya and Render 1 Layer and Voila! Done...

Time wise it's very different to just encode a file sequence to a quicktime or something within after effects, than to bring in 9 Layers to animate the opacity, right after going through the hassle of Making 9 Render Layers in Maya with shader overrides...don't get me wrong...it still pretty simple...but repetitive tasks like these are a little annoying.

Thats all we're trying to say...please stop judging peoples opinions or comparing ones thought with something stupid like your photoshop example...remember it's just an opinion and a thought...:shrug:

If you don't understand our way of thinking, it may be because you don't understand tight deadlines that require heavy compositing in a "do it all yourself" environment, you may be used to a workflow where work is passed on to someone else and you don't deal with it anymore...or you just have more time to do things than others...which is perfectly fine...in my case it's quite the oposite, that's why I had my opinion. Please respect it.:)

Emil3d
08-08-2006, 02:09 AM
Again I would say sorry if my messages are causing you grief. I would never do that deliberately to anybody. I simply believe that my suggestions are helpful and I’m trying to convince but I guess I’m not a very good writer.:shrug:

The purpose of my last messages here is really to understand why for some of you it is so harder to do what I find so easy and eventually to exchange ideas.

Well, sorry again and hopefully Maya one day will have what you want. I really wish I’m wrong and there is a faster and easier way than using post.


Take care.:)

kyleb2112
08-09-2006, 03:03 AM
Yeah, fading layers is easy in post. But having that control via Maya's Animation controls, driven keys, and scripting would be a huge benefit. I just finished a project with hundreds of 3d bubbles that needed to fade in and out in sync with narration. The inability to sync the fades in maya along with the rest of the animation was a huge headache. An animatable float value for visibility would have allowed me to scipt it along with all the rest of the things I had automated.

You can do glows in post too, but that doesn't mean they're superfluous in Maya. In fact, object fades as a Maya post process might be the way to go.

Emil3d
08-09-2006, 06:01 AM
Yeah, fading layers is easy in post. But having that control via Maya's Animation controls, driven keys, and scripting would be a huge benefit. I just finished a project with hundreds of 3d bubbles that needed to fade in and out in sync with narration. The inability to sync the fades in maya along with the rest of the animation was a huge headache. An animatable float value for visibility would have allowed me to scipt it along with all the rest of the things I had automated. ...All of this is available and easy for me currently in Maya.

All I would have done is, instead of the visibility value that you are missing, use the currently available Matte Opacity value of the bubbles' shader and put them in a Render Layer.
Render as PSD layered file format. After Effects reads and loads layers automatically from PSD files.

Having said that, I don’t mind at all if Maya alone can do that easier, faster, and more efficiently but unfortunately as far as I know this is quite challenging and is no where near the same as applying glow as post effect.
I would love to be proven wrong however

almux
08-09-2006, 10:46 AM
almux, fading a character out of a scene would require just 2 layers a character with an alpha mask in the top layer and the rest of the scene in the layer below. In the compositing program just animate the transparency of the top layer (character) for certain number of frames and all programs can preview the result in real time and you will have the flexibility to quickly check different durations for the fading transition and even graph the fading against the time.

In general everybody uses a compositor to assemble animation produced with a 3D program anyway. If you have a scene where only the character moves and nothing else you don’t want to render the same background for each frame again and again. You just render one frame for the background and in the compositor you just tell it how long to repeat it. These are just a few of many many other benefits to render scenes in separate layers (passes)

Of course, with a simple and far enough background, it is the smartest. But in most cases a caracter is moving within a complex scene and its shadow has to get convicting althrough its fading away. I usualy make a separate "peudo" shadow and composit it in a complementary layer in FC... but its all manual working on the timeline (takes a lot of time).
It is nicer to have a strong rendering 3D app on wich one can have the caracter and its shadow catch on real deformations.
I'm not yet at the point of Maya training to do that... but there must be some "easy" way to have successful results...

Emil3d
08-09-2006, 12:00 PM
…But in most cases a caracter is moving within a complex scene and its shadow has to get convicting althrough its fading away. I usualy make a separate "peudo" shadow and composit it in a complementary layer in FC... but its all manual working on the timeline (takes a lot of time).
It is nicer to have a strong rendering 3D app on wich one can have the caracter and its shadow catch on real deformations...The background catching the shadows is a typical 3D effect and Maya is very good at doing this.
All you have to do is put in a render layer all objects, and lights that contribute to the creation of the shadow, right click on the layer and choose Preset > Shadow and that’s it.

And since you mentioned that you are new to this here is a quick tut if you want to check all this in action.



Create a new scene, Open Render Globals, and for the image format choose PSD layered.
Create a plane, a sphere on it, and a light illuminating the sphere and casting a shadow.
Select the plane and the light, and in the Render Layers click the “Create new layer and assign selected objects” button
Select the plane, the sphere, and the light and in the Render layer click the “Create new layer and assign selected objects” button. Right click on that layer and choose Preset > Shadow
Select sphere, and the light and in the Render layer click the “Create new layer and assign selected objects” button
Batch Render
Go to the image directory of your current project and open the Photoshop file with the name of your current scene.
In Photoshop select the first layer, press Ctrl + E, and then drag the opacity slider and voilà you have a fading object along with its shadow.:)

almux
08-10-2006, 06:49 PM
The background catching the shadows is a typical 3D effect and Maya is very good at doing this.
All you have to do is put in a render layer all objects, and lights that contribute to the creation of the shadow, right click on the layer and choose Preset > Shadow and that’s it.

And since you mentioned that you are new to this here is a quick tut if you want to check all this in action.



Create a new scene, Open Render Globals, and for the image format choose PSD layered.
Create a plane, a sphere on it, and a light illuminating the sphere and casting a shadow.
Select the plane and the light, and in the Render Layers click the “Create new layer and assign selected objects” button
Select the plane, the sphere, and the light and in the Render layer click the “Create new layer and assign selected objects” button. Right click on that layer and choose Preset > Shadow
Select sphere, and the light and in the Render layer click the “Create new layer and assign selected objects” button
Batch Render
Go to the image directory of your current project and open the Photoshop file with the name of your current scene.
In Photoshop select the first layer, press Ctrl + E, and then drag the opacity slider and voilà you have a fading object along with its shadow.:)


Accept my gratefullness! This is great! I'm still running through the 3 books of Learning Maya 7 going back and forth adapting the "exercises" to my purposes.
But what really helps are pointings out like yours.
In a prime time, it's going to save me lots of hours of patient work and (sooner or) later it will increase and multiply my mentionned "purposes"!
Thank you!

kyleb2112
08-10-2006, 09:37 PM
All I would have done is, instead of the visibility value that you are missing, use the currently available Matte Opacity value of the bubbles' shader and put them in a Render Layer.
Render as PSD layered file format. After Effects reads and loads layers automatically from PSD files.

Finally some useful info. I played around a lot with the Matte Opacity, but didn't think about render layers+psd files. This probably would have been unwieldy for the hundreds of bubbles project, but it'll come in handy in the future. Thanks!

CGTalk Moderation
08-10-2006, 09:37 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.