Ara's Tale - short film wip

#41

Wish you all the best for the Suzanne Awards 2011, with some luck, we’ll be competing against each other :wink:

#42

Thanks Stephan !

That would be a real fun.

See you in Amsterdam :slight_smile:

#43


A quick update only.

I started to texture Ara’s face. The shader itself is only a plain lambert shader where I use some color maps to preview the painting result.

To have some guidance later in the texturing process, I rendered out a test render with the current state of texturing and than I started doing paintovers in gimp.

These experiments are not finished, but I wanted to show one result of these tests.

n the short I will use some sort of multi layered SSS skin shader but I have to experiment a bit with these to see how to approach the painting of the different skin layers to get the desired end result.

#44

I had a go with multi layered SSS some times ago and that didn’t convince me.
I found it far more easy to use a simple SSS . I’m not saying it’s not a good trick or so, but it is so time consuming in the render time for no real benefit comparing to internal SSS, that I prefered to stick to something more classical and efficient.

#45

@Stephane: Thanks for the input. I did some extensive testing and will stick to a sort of 3 layer sss for now as this gave me the best results.

update:

This post marks the end in my various experiments and explorations to get a fairly plausible skin for Ara.

The result you see above is based on the 3 Layer SSS approach. Ben Simonds does a a very good explanation on this topic.

In the comments section of Ben’s post are some interesting links to papers giving quite a good insight into this problematic area.

The basic setup as described in Ben’s post is here too, but after a lot of experimentation I expanded the nodes a bit:

[ul]
[li]I use an additional sss mask for blending a sss version of the subdermal sss layer with a non-sss one. This gave me better control for applying the sss effect.[/li][li]I modified the specular term by simulating a type of fresnel specularity. In my opinion this made a huge difference in the skins appearance.[/li][/ul]It also took quite some time to develop a workflow for texture painting. I did a basic material setup in blender 2.5x with the 3 layers as texture slots and using the same mode as in the original material setup. Using GLSL materials I could than texture paint relatively easy.

But due to the fact that the 3 layers are combined using the screen mixing mode it took some practise to find the right colors to use. To have at least a bit of a non-destructive workflow, I used various layers for the skin details.

Interestingly the biggest problem in the end was to apply the brow texture. Usually you have a texture map with just the brows painted on an alpha only map. As texture layer you just mix it with 100% on top of the other textures. With the multi material setup where all the layers are cumulative I did not find a way to do this easily.

The node setup right now demonstrates for me that this approach is working. On my todo list for the skin shader is:

[ul]
[li]convert all color operations to a linear workflow correct version (screen -> add,
)[/li][li]clean up the huge amount of work done by all the extra texture layers by combining them into one or baking normal maps.[/li][/ul]The image shown above was rendered at 75% of the final resolution ( 1920×1080) and was slightly over my limit of 3 min per frame ( 3:15). I hope to reduce the render time with some of the cleanups mentioned above, but the biggest part took the hair anyway (~2 min).

I have to confess, that I may have overdone it here in regard to realistic display. I have to render a shot to see if the animation doesn’t look too clumsy now, in which case I even might consider tuning down the skin shader.

And btw, if anyone is wondering, the lashes are still missing.

#46

After finishing the skin shader one of the last things left to do was to create Ara’s eye lashes.

From my first research on hair it was relatively clear that the eye brows and eye lashes would have to be implemented using textures. I did the brows already during the development of Ara’s skin shader.

For the lashes I started with polygon meshes attached to each eye lid. Alpha mapped images of the individual lashes were applied via appropriate uv mapping.

It did work, but not really to my liking. Using this technique I created lashes which were essentially 2-dimensional ( aka flat). And not only this, but the roots of each lash hair were in a more or less straight line. This is ok if Ara’s is seen from a distance but gets increasingly annoying in closeups. And said closeups definitely make their appearance throughout Ara’s Tale.

Mark Nyman (chipmasque) mentioned that he created lashes using 3 different techniques and his favorite was implementing the lashes using a particle hair system. After some discussion about the scaling issue with hair in blender I nonetheless tried the hair approach.

This is the parameter panel for the strand settings for the hair shader. As the input fields for ‘Start’ and ‘End’ suggest, it should be possible to enter values to 1/1000th of a blender unit. As my previous tests showed 1/1000th blender unit was just 2 to 3 times bigger than lashes for Ara’s would have needed.

In a total rush of optimism I tried to input my needed value 0.0004.

And

SURPRISE

the values are correctly interpreted, its just the display values which get rounded to the nearest 1/1000th.

This made things different. I setup Ara’s main hair with blender units using the ‘hidden’ scaling feature and what can I say: I just worked. Not only that I worked better than using the pixel based approach, as now the hair is always displayed in the correct width, regardless from how far away the hair is seen. I still use the child simplification technique to lower the rendertime with no ill effect so far.

The only drawback with this method is that you have to memorize somehow the actual values you entered. Because the next time you go he the input field it is reset to the nearest rounded value. Further experiments showed that the input routine accepts and correctly interprets values down to 1/100000th of a blender unit.

This is absolutely cool !

Another topic since my last post were shape keys and their intrinsic behaviour. During a discussion in my wip at blenderartists I realized that a lot of the corrections I made to Ara’s base mesh weren’t visible in the renders. It turned out that my understanding regarding shape keys (morph targets) was wrong.

A big thanks go to kram1032, who suggested to introduce a new shape key which holds all the corrections to the base mesh and is always fully visible. This trick is simple and just works wonderfully.

The image on top shows the current state of Ara with all these new techniques applied. And because its just nice to see here is a link to a Full HD version of that image.

Whats left to do for Ara is texturing the hands and feet, which I already have began. The shader will be simpler than the face skin and I do not expect any surprises here ( now why does that sound odd
)

ps: after seeing sintel ( very impressive: storytelling, cinematography, cg technique; a very satisfying experience) I am now even more motivated to finish Ara’s Tale.

#47

After fiddling with the skin shader and lashes for Ara, I thought it a good time to start to experiment with some lighting and compositing work. The main idea being to have an environment to test the different shaders for Ara and to spot some possible problems.
I chose the very first shot as test bed for my experiments.

I use all linked assets into my scene files and the last addition to Ara were her lashes – as separate objects – so I linked those as well and
first surprise ! The lashes imported but never linked correctly to my armature proxy. After some fiddling I decided to completely reimport Ara and associated objects. I have the feeling that I might might be doing this more often in th future, so I made a quick howto for me to not forget all the small little details to get it right.

Next came the baking of the cloth simulation. I had already invested quite some time into this topic, so it should just be a setup-click-and-wait kind of thing.

Ha, so wrong !

I the past I had concentrated on the skirt part of Ara’s dress and quite neglected the upper part. Now I had a wider view and recognized that the current setup just isn’t working. This insight resulted in a separate collider object for the dress, a reworked weight-painting and remodelling of the dress mash and dress colllider as well as a slightly different setup for the cloth simulation itself.

Its better now, but I see now that I will have to refine this from shot to shot.
Ok, next came the lighting setup – no real surprises here (for the moment) – and accompanying the compositing part.

The topics I wanted to cover were

[ul]
[li]separate layers for each light group (main, ambient, moon, cage lights …) for each part (background, Ara, cage) to have maximum freedom for balancing the lighting[/li][li]vector blur for all objects[/li][li]DoF[/li][li]Play around with some nice glow effects[/li][li]Find a way to light a night scene with a path in the shadows of moonlight were the main light source is coming from a cage.[/li][/ul]Well, the first point in the list was easy.

The funny things started when I tried to use the vector blur. I have Ara and the cage on different render layers and combine them using the Z-Combine node. Well when using the vector blur ( or any other blur node) this will not work correctly anymore, as the z information is sharp and not blurred at all ( and this isn’t possible anyway). I have not yet a solution, but I have to somehow create a mask originally derived from the z-buffer of both layers and apply the same filter operations on this mask as well. At least thats my theory for now.

Pure alpha-over will not work, as I have intersections ( Ara holding the cage).

Another thing which is bothering me is that I do not seem to get a vector blur on my background, which is realized as set ( set in the render panel, where you do not have any selection possibilities). I have to investigate this further.

Another immensely annoying thing suddenly popped up again: all seams on Ara’s dress were clearly visible again. I thought that baking the normal map from bump maps in blender 2.5x was the solution for this ( see this post for more info ). As it turned out, this is not he solution, as blender 2.5x has the same behaviour.

After long ( very long) experimentation I finally found the culprit which causes this:
It seems (no pun intended) that around seams blender is using areas of the texture map beyond the actual uv-mapping, maybe for blending/smoothing purposes. The default setting in texture paint mode for the projection painting is to have a bleed value of 2, which means that blender will paint also 2 extra pixels outside the uv-mapping. This value is ok for color maps but obviously too small when drawing bump maps. An increase to 4 or higher solves the problem – in principle.

What it means for me is that I have to repaint all seams in the bump maps on my relevant models with a higher bleed value

The DoF point was another source of new work. In the early animation phase I created a camera rig with all nice controls for positioning, targeting and controlling the lens value. What I didn’t think of at that time was to include a control for the focus point as well
Ok, time for a new reimport session for the camera rig.

And finally I quite clearly see that a lot of polishing will have to go to the animation done so far. But that was to be expected.

All in all a very informative and in the end productive weekend. To show you the outcome of all these explorations I have uploaded a 4 sec shot of the shot. It’s a very early glimpse of what is to be expected and still no vfx ( glowing lights) done here. The irony here is that in this clip Ara’s hands are rendered black due to rendering time constraints.

vimeo link

#48

Nice progress. Seems you’re learning a lot from this project. Using planes for eyelashes really does produce a plain face. You may wanna twist the plane as it goes to the outer part of the eye to make it more or less realistic and turn alpha shadows to the eyes and the head.

#49

Thanks icecooly. Yes the learning experience is huge, sometimes even overwhelming :), but thats one of the main reasons to do this project.

I do not use alpha planes anymore but use a hair system for the lashes, which works quite well.

#50

http://www.youtube.com/watch?gl=us&warned=true&client=mv-google&hl=en&v=e_az0dhyuv4
I’ve actually done my own. Here’s the link. What do you say we collaborate on another short, you and me? I’ve had my own experience. It’s not the best short but i know more or less the process.

#51

I have just now seen your post, sorry for not responding earlier.
The link you have provided does not work anymore.

About doing a short in collaboration: right now I am fully occupied with my current project. I plan to do other short projects in the future, but have no specific timeline. The next short should be in collaboration and I may come back to you.

#52

As I am not allowed to post a bigger number of images I refer to my current blog entry about the current state of compositing.

In this post I ramble a bit about all the obstacles I found trying to find a suitabl workflow for the lighting/compositing stage.

Sorry for the detour.

#53

alright. just let me know.

#54

I just wanted to say that I really admire what you and other blender users are doing. Your animation is coming along nicely, and I’m following along with great interest. It really is amazing the strides that have been made in the open source community. It’s very tempting to get involved and develop a linux based workflow. If I wasn’t so busy, I’d love to spend time learning blender.

I dabbled in some linux cluster work with drqueue a few years ago with limited success. I think there is great potential in open source.

The visual style you’re achieving is great! Keep up the good work.

#55

damn nice work !!
Love it :smiley:

#56

Thanks a lot for the kind words, its surely helping my motivation :slight_smile:

Regarding the opensource workflow. This is not an easy road to go. And to do a whole production only with OSS Tools is extremely tedious, sometimes ineffective and some things simply can’t be done.

BUT, its opening possibilities and experimentation for me (and a lot of others) which wouldn’t be possible otherwise.

I do not want to rely and pirated versions or crippled demos. And additionally I am in the fortunate position to actually be able to read, understand and change code, so I can fix some things by myself.

#57

With a lot of iterations, tries and errors I managed to finalize the first 3 shots of this short. And when I say finalize, that doesn’t mean that they are never to be touched again, but that these shots are very near to the that version, I will call final ( in some not too distant future I hope
).

Even though very exhausting, I deem these last days as very valuable as learning experience in the area of lighting, render layer organization and finally compositing.
Each of these shots had its own unique difficulties and I had to discover them all and had to find solutions and sometimes workarounds for them.

Some of the problems encountered with the first shot ( the cage closeup) I already discussed in my previous posts, so I won’t go into any detail here.

Shot 2

For shot 2 I have a long shot where Ara walks across the bridge. It is night and yet I want to be able to see the environment. It turned out, that for these long shots it won’t be necessary to use SSS and thus hugely simplify the render setup. The most work here was to find a proper balance between Ara and the environment and to give everything a convincing depth. During my first tests I always got a – what I call – studio look, where you just didn’t buy that this shot is actually taking place in the open. Its still there but much better now.

An interesting problem surfaced with my kind of workflow I am using here.

I usually setup the lights and renderlayers and render 3 to 4 shots covering the whole shot sequence. I render these shots with 50% of the final resolution. If everything works ok, I turn on my render server and create a 50% resolution raw render sequence and feed it through the compositing network. With this I see the first time the animated result and can easily spot discontinuities in light and colors. These can be fixed, sometimes with animated values for the various control parameters.

This gives me a ‘final’ node setup and its time to render the shot in full resolution, feed it into the nodes and hopefully have a final shot in full resolution.

It turned out that the luminance of some of the glow effects are dramatically higher when going to higher resolutions. I have yet no idea why this is so, but this just adds another loop in my workflow iteration toward a final highres shot.

Shot 3 (see image on top)

Shot 3 is a medium shot on Ara. SSS was not to be neglected here and I have already discussed the issue with splitting lighting into renderlayers and SSS in this post. I have posted a detailed breakdown of this shot on my blog already, so just a few highlights here.

Hair turned out to be a massive troublemaker in regards to rendertime. The need to split the SSS layers to extra scenes and the wish to have have full control over the individual lights during compositing led to a setup where the hair gets rendered five times for one frame. On my quadcore a 50% resolution frame now takes ~ 6 minutes to render going up to ~ 20 mins for a full res frame. I tried several approaches to reduce the time doing compromises but in the end returned to my original render setup. It takes time but it give me the best results.

Another nice coincidence was the announcement by Sebastian König of his compositing tutorial. I actually bought it and went through all the 5 hours of material. While not telling me something fundamentally new it was filled with various gems of bits of knowledge and just niceley expanded my current knowledge of this topic. For anyone wanting a more in depth look into the compositor should really consider this one.

And now after so much talk I proudly present a release candidate of the first 3 shots of Ara’s Tale

link to vimeo video

And finally something for the readers interested in some statistics:

current amount of hours spent: 919

1 hour of rendering on my renderserver (only one at the moment, so only 12+12HT cores) takes 0.3 kwh. Shot 3 took ~3.5 hours to render the 50% resolution version and thus used ~1kwh, which translates to ~0.18 € in the place where I live. I have attached a watt meter and currently the total consumption is at 17kwh.

#58

Very nice! It’s nice to see someone thinking about power consumption too. That is what ultimately caused me to abandon my cluster endeavor too. At some point you have to consider cooling costs into the equation.

Here’s my $0.02 on the crossing the bridge shot. Just a suggestion. It’s ultimately your project, and this may be counter to the feeling you’re trying to convey. I just thought it might add to the “look”.

#59

Thanks a lot phildlight

Yes, this must not be overlooked, especially when paying it from your own money. But I think my current setup has a very nice cpu power/watt ratio.

Thats the look that will come a bit later in the short when Ara is standing on the ledge. I have thought about a reddish glow from below to add to this set as well. Depending on one of the following shots I will see if I have to add this.
But in any case it won’t be so much as in your quick sketch. Storywise there is a reason that the light from below should be almost non-existent in the first set.

#60

next update:

I thought this would never happen, but slowly something like a production routine is taking hold of Ara’s Tale.

For the past days I was busy working on finalizing 5 more shots and could actually reuse knowledge gained from the previous shots. I now know for the current setup how to achieve the desired effects and how to setup the lighting and needed render layers. The same is true for working with the compositor, where I can now reuse a lot of node groups and techniques created so far.

That doesn’t mean, that its now an automated procedure, but there are no detours and breaks due to unwanted surprises along the road (
so far ). I can now concentrate more on the look and feel and not bother so much with the technical aspects.

I plan to do 5 more shots and then release a preview of the first 80 secs, which I think will conclude the publicly shown shots.

Depending on the material, there might be some positive effect of doing a teaser/trailer. This could be used as test bed for the collaboration with my sound and music experts, but that really depends on their time schedule and possibilities.

Here are frames from each of the 5 shots I have done the last days. These stills are taken directly from the shots. The resolution of these shots is currently 720p. ( click on the images to view the full resolution )