Eyelashes as Eye Opener

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.

Karl 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, ts 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.

Author: loramel

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