Finished Render


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MOD_CAM

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DOP_CAM_01

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DOP_CAM_02

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DOP_CAM_03

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DOP_CAM_04

Theme of the assignment

"When one door shuts, another opens."


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The basic idea is: 

A Möbius Strip

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A rendering with maya fur at the density of 100000.

and RenderMan environment light for the occlusion shadow.

Finished (without glass globe)White ModelOcclusion Pass

Sample Rate Test



The higher the sample rate value, the lower the render resolution.

In order to test the render quality using maya's procedural wood texture, the sample rate is set to 10. Notice the aliasing effect, it is due to the high sample rate value. (Fig.1)





When reduce the sample rate to 1.0, the aliasing effect is suppressed, but the result is still not acceptable. (Fig.2)

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Rendering test using maya procedural wood texture.

Base Texture

Maya procedual wood texture

(will be changed to bitmap texture)

Strip Texture

3D painted texture using Autodesk Mudbox

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Glass globe from top side view

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Glass Shader

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Using Pixar's glass shader to create a double-sided glass globe.


When disable the Raytrace Shadow option, the inside of the snowglobe will not be lit. (Fig.1)





When enable the Raytrace Shadow option, the light can go through the glass globe and lit up the inside. (Fig.2)


Render quality of Glass Shader

There are two value which control the glass shader's render quality, one is Refraction Sample under slim editor, another is Shading Rate under render quality control panel.

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(above) Keep the default refraction sample value, which is 1, and maintain the shading rate at 1.0.

We can see aliasing at object edges, and pixel dots on grass. The render quality is not acceptable.

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(above) Increse the refraction sample to 16, while maintain the shading rate at 1.0.

This setting gave us good quality on objects inside the glass globe, but cannot fully supress the aliasing on grass.

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(above) Keep the refraction sample at 1, but increase the shading rate to 0.1.

We can notice that the anti-aliasing is at good quality and the grass is sharp.  

Thickness of glass globe model

Two-sides polygon glass globe model, the distance between two faces is 0.1 unit.

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Two-sides polygon glass globe model, the distance between two faces is 0.5 unit.

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Two-sides polygon glass globe model, the distance between two faces is 1.0 unit.

Texture

The wood shader is a blinn shader with hand-painted texture using Autodesk Mudbox. Below are some test renders for the bump map.

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Wood Base Texture - Diffuse Color

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Möbius Strip Texture - Diffuse Color and Bump

mobius strip specular

Möbius Strip Texture - Specular

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Wood Shader

Bump Value 1.000Bump Value 0.500Bump Value 0.250Bump Value 0.100

Output Channel

Below are images of the same rendering's different output channel, which can be used as compositing elements in later post-production workflow.

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Conclusion

The goal of this project is to know the basic concept of RenderMan. A snowglobe scene was required for testing purpose. Though it is for technical study, it still has a theme of "When one door shuts, another opens". 

Instead of being realistic, my idea went to symbolism. Inspirations came from sources such as Möbius Strip, Yin-Yan, and the work of Dutch artist M. C. Escher.

When rendering the scene, I discover that RenderMan can very efficiently render high quality 3-D scene with subdivision model, fur, HDRI image-based lighting, and Depth of Field. 


RenderMan is sophisticated. It is not easy to use, of course, not intuitive, comparing to other renderers such as Mental Ray, VRay or Maxwell. But this is why it's so advanced and industrial standard. It provides us the infinite possibility of what we can do when rendering a 3-D scene.

However, using RenderMan do requires some fundamental knowledge about computer graphic and programming. That will be the primary goal of the following assignments in this course. 



Below are some other renders from different camera position. The average render time for images below (at 1920 x 1080) are 3-5 minutes per each one.


© Ziye Liu,  2012