Miscellaneous: Motor Cortex Test (fun, try it)

This is fun to try:

If you are sitting around one day and want to reveal something about your brain's motor cortex, try this trick:

Without anyone watching you unless you want to recieve a concerned look.
Also, it's extremely important that you follow the left / right accurately or it won't work.

1. Sit in a chair
2. Lift your right foot about 1" off the ground.3. Move your foot in clockwise circles.
3. Keep doing this.
4. Hold up your RIGHT hand in front of you.
5. In the air write the number "6" with your finger

~~~Your foot will change direction.~~~

Comment on your own results (unofficial poll) let's see how many people are immune!

Keeping in mind, of course, if your foot doesn't change direction, either something is WRONG with you, or you didn't do it right :).

Rendering: Subsurface Scattering and the Architectural Shader...

Task: Render transparent silicone with the sss effect but without the complexity and rendering cost of gi, caustics, or fg.

For product rendering the mia_material_x is a great shader, it has most of the features needed to simulate all kinds of materials. What it does lack, however, is a decent way to show believeable translucent materials like silicone.

The translucence feature of the mia_material_x only really works for paper thin objects, and even then it provides, I believe, only the back shadowing.

misss_fast_shader, does a very decent FAKE job of sss estimation... however, it does not have a facility to be transparent at all.

Solution:

1) create the misss_fast_shader,
2) assign it to your object,
3) check the box under algorithm control "Scattered Component Only"
4) create the mia_material_x shader,
5) connect the misss_fast_shader.outValue in to the mia_material_x.additional_color
6) connect the mia_material_x shader to the shading group that is connected to the misss_fast_shader (this will mean that the lightmap and other nodes will already be connected up, and we're done)

of course, you'll have to tweak the colors of the sss to look correct for your materials, but that's essentially it!

Shader Network as described.

However, there are still some issues with this shader combination, and I will describe them in another post.

----- here's a hint: "Shadows should not be sharp from an object inside a translucent material" more exploration is needed! ------ will get back to you soon.

----- I just found Master Zap's article about plugging certain aspects of MIA_MATERIAL_X into the MISSS_FAST_SKIN_MAYA... however he does this for max, and well... I don't know how to port that .mi file over to maya... yet. Not even sure it solves the issue. However... going to give it a shot.

------ another note. Shadows, apparently, cannot be "glossy"? or to be more specific, shadow shaders, can't do blurry shadows. (raytrace, or mapped)
(blurry shadows from diffusing materials requires using GI and/or caustics, I think it's because when you're tracing back to the light through a transparent object, how do you know where you are? are you inside the penumbra, or the umbra? obviously, photons solve this. And with newer versions of mental ray, at minimal cost (compared to the effect)

Introduction...

I'm creating this blog at the suggestion of a good friend who I babble on about shader ideas, and tips, tricks and, of course, complaints about typical CGI stuff.

Probably the most important is the complaints, because often times it is when we are discussing these complaints, that the greatest level of understanding comes about, and many times a good solution.

I will admit, I am not the world's foremost expert on Maya, mental ray, Rendering, or Shader writing, however, I enjoy working with them, and have a fair bit of experience with them as well.

I also hope this will help others overcome some of the hurdles I've found in my quest to understand the art of simulating light.

Thanks for reading, hope you enjoy this.