All posts by Lee Griggs

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About Lee Griggs

In-house artist at Autodesk working on the Arnold renderer. http://arnoldrenderer.com

Wax Crayons – alLayerColor and Utility shaders

crayons-2k

I wanted to tint the color of the paper covering of some wax crayons. So, how to do this without having multiple colored paper textures for each wax crayon? The alLayerColor shader from the very cool alshaders by Anders Langland in combination with the Ai Utility shader is perfect for this kind of thing.

By setting the Color Mode of the Ai Utility to ‘Object’ each of the crayons will be randomly tinted because Object mode uses the name of the shapes to compute the color. Ensure that the ‘Shade Mode’ is set to flat as we don’t want any shading effect from the Ai Utility shader as the alSurface shader is being used for the wax and paper.

utility
‘Shade Mode’ set to ‘flat’ and ‘Color Mode’ set to ‘Object’.

The Ai Utility and the grey paper.jpg texture are combined using the alLayerColor shader:

paper
Paper.jpg layered with Utility shader using alLayerColor connected to Color of alSurface ‘Paper’ shader
alLayerColor
alLayerColor connected to Diffuse Color of paper. Mode set to ‘Color Dodge’.
grey-crayon
Grey paper texture without alLayerColor
pink-crayon
Grey paper texture layered with Ai Utility using alLayerColor shader

The same Ai Utility shader is also used to alter the Diffuse Color and SSS of the wax alSurface shader.

wax
Ai Utility driving the ‘Diffuse Color’ and ‘SSS’ color of the wax shader.

9624b657a165427e3e342793bd310603

Try Arnold

pills-1k

I thought I would have a go at testing the alLayer shader which is part of the alShaders by Anders Langland with Arnold for Maya.

So I used the alLayer shader to layer two alSurface shaders together using an image of the text connected to the Mix attribute of the alLayer shader. The Mix image acts as a mask between the two layers. Therefore, the text will use the dull rough specular of the alSurface shader and will appear as if its floating above the bright sharp specular of the other alSurface shader.

pill-shader

The nice thing about the alSurface shader is that it has two specular layers. This enabled me to add two specular effects on the pill. The first specular is sharp and the other has a higher roughness value to give a smoother hi-light.

alsurface-pill

I used Arial bold for the font and used the ‘Photocopy filter’ in photoshop to give the impression that it has been printed badly onto the pill as I liked the way it merges some of the text.

pill-text

A 3d texture projection was used to precisely project the texture onto the pill. When I originally positioned and scaled the projection node it cut off the beginning of the Solid Angle text. I kept this effect as I noticed that the printing on pills isn’t perfect.

allayer-label

The scene is lit with a hdri connected to a skydome light with two long thin cylinder area lights to add specular reflections along the ‘hero’ pill.

pills-lighting

Finally, thanks to a suggestion from Angel Jiminez, I thought I would have a go at mocking up a fake advert for Arnold.

try_arnold