Maya MASH Painterly Shader Exploration

Per a request, I am currently in the process of replicating a surface-level painterly effect in Maya with the use of MASH.

The reference I was given was the style of the short film I am a Pebble. Here is a screenshot comparison I made from images available in their production section - with and without the shader:

I was notified that Maya's MASH would be the way to go about replicating the effect.

The biggest issue encountered is that aiFacingRatio and Orient to Camera do not function simultaneously. One is basically left with one of these two visual choices:

aiFacingRatio but no Orient at Camera Orient at Camera, but no aiFacingRatio

To make aiFacingRatio take effect on the MASH'd planes one would have to bake out the plane orientation and apply aiFacingRatio separately.

This shader can be applied onto any Mesh other than a Sphere, but we are using a Sphere to demonstrate how to apply the painterly effect. The steps to recreate the MASH are as follows:

- Create your mesh, add an aiStandardSurface (Mesh_Surface) to it and plug in your texture, ramp, or visual surface of choice.

- Create a plane, reduce its subdivisions to 1x1x1, add an aiStandardSurface (Brush_Stroke) and apply an opacity mask to it (Geometry > Opacity). To create a painterly effect I plug in a mask of a brush stroke.

- Erase history (Edit > Delete by Type > History) and freeze transformations (Modify > Freeze Transformations) on plane.

- Select the plane, go to the MASH tab, and run MASH.

- Open the MASH Editor.

- Under MASH_Distribute switch the Distribution Type to Mesh.

- Set the Method to Random Vertex.

- In the Outliner select your subject and middle-mouse drag it into Input Mesh.

You will see that the planes have placed themselves onto your subject.

You can increase the quantity of planes on the Mesh at the top of MASH_Distribute.

- Select the head MASH from the list and in the “Add Node” panel add a Color Node.

- Under MASH Color middle-mouse drag your Mesh into UV Mesh.

- In Color (above UV Mesh) plug in an aiStandardSurface (MASH_Input).

- In the Node Graph editor under Hypershade plug in your Mesh shader’s (Mesh_Surface) Out Color into MASH_Input’s Base Color.

- In the Hypershade Node Graph open the graph for your equivalent of the Brush_Stroke surface.

- Create an aiDataColor node, plug in the colorSet data set into Attribute, and plug the aiDataColor node into Brush_Stroke.

- Under MASH ReproMashShape > Arnold > Visibility check Export Vertex Colors (on) and Casts Shadows (off).

This is the process of setting up for a painterly effect.

To make your planes face the camera:

In MASH add an Orient tab, Under Aim at Target Options middle-mouse-drag the perspective or intended-for-render camera into Target.

To make your planes look organic:

In MASH add a Random tab. Mess around with the sliders. Randomizing size and rotation will yield best results.