Paint Effects City

Week 11

After the grass, rocks and trees, the next challenge to tackle was the city in the distance. To create the impressionistic style of the city from my concept I figured that simple building shapes that could catch the light would be enough. With not a lot of time left, Paint Effects seemed to be the quickest solution, plus I really enjoy how organic the process of distribution feels with Paint Effects. Unfortunately, I haven’t yet been able to figure out a method of distributing my own geometry with PFX so I resorted to using one of the default building brushes from the visor database.

I found that PFX will paint shapes perpendicular to the surface which is made paintable. This was a problem for my city designed on a steep hill and I found that adjusting the elevation produced too random of results (as one stroke had more than one house). I had houses pointing in all directions. I tried stacking planes which intersected the hill and painting on these instead. This method wasn’t perfect as there were some floating houses once I hid the planes but I got away with it seeing as the city was so far away and the style was more abstract than realistic.

Even though I tried to paint only on areas that would be seen, I still ended up with quite a heavy load of building geometry and some excess. After some frustration I remembered file referencing which I realised I haven’t been using enough of in the past. Even with using file referencing though, it still took a long time to load materials and switch between render layers with materials applied. Rendering was extremely quick though. Also, I built this approximately to real life meters which I’m not sure how necessary that was. I thought it might aid the parallax effect if we wanted to test the camera in Maya. Does the size of a polygon influence memory usage or is it just the number of polygons? Probably just the number right?

For shading, I used a ramp shader and directional light set-up similar to what I used for the rocks and played with the hue/saturation/brightness of the incandescence and shadow colour. For the water I used a reflective shader on a polygon plane and for the land I used a second plane placed over this with a transparency map made in Mudbox to indicate the coastal line. The land in particular needs developing. I was planning to make it seem at least more mountainous/hilly and perhaps indicate more forestation somehow.

Some render tests/progress:

Molly painted a sky which I tried adding to the scene also. The area light which I used to light the sky influenced the colours quite bit. I also haven’t added the clouds yet.

I rendered selectable areas for the sky, sea and land for colour correction in After Effects. This is the scene so far. We have yet to play with the characters in the scene and the environment still needs developing.

Stargazing: Rocks

Week 11

Getting the form, lighting and texture in 3D to fit the style which we wanted took a lot longer than anticipated. This is the aim which I wrote out for myself when I started:

“Make the rocks so matched to the painting that it would be impossible to tell that they were 3D if you composited them side by side into the painted concept. But, don’t let the concept dictate all, feel free to develop and improve when the opportunity arises.”

I started by taking the blocked proportions of the dolmen into Mudbox for sculpting. Although rock seems like a simple thing to sculpt it took me a while to get suitable forms. My first attempt was too rough and digital-clay like and looked even worse  when I tried to render the detail with a displacement map in Maya’s software renderer.

I looked up how to improve maya software displacement map settings but discovered that Mental Ray is a wiser choice for displacement maps.

I worked on a single rock, modified in Mudbox, for a while to see if I could achieve the style. I tried making very hard edged light by adjusting the intensity of a directional light. To create the fine carvings, I first tried using the knife tool in Mudbox but this gave me very lumpy results even after using the smooth and scrape tools. I also tried using the freeze tool but couldn’t create the desired results. I found that making a displacement map in Photoshop with a hard edged brush gave a much cleaner result and also maintained the smaller detail of the brush’s edge. The depth of this could then be increased by adjusting the alpha gain of the image file so as to make deeper shadows. By adding a few edge loops I could make hard rock edges without too much resolution and I tried bump mapping a canvas texture to see what this detail could look like.

From talking to Clare I was directed to look at the ramp shader with shading set to light direction and interpolation set to linear. From going through the ramp shader attributes I found that I could make the shading even more graphic like the painting if I cast the scene in shadow with a box and used the shadow colour to control the light colour and the incandescence to control the shadow colour.

The depth of the bump map, made from painted/canvas texture, controlled the detail on the interface between shadow and light giving a painted/dry brush edge to this area.

To create the rock shapes, I imported my blocked versions from Maya into Mudbox as these had roughly the silhouette and volume that I needed. I made the mistake of spending time UV unwrapping my modified boxes as I thought I would be applying maps onto them. As simple as they were, they still took time to unwrap using planar mapping as there were a few of them. Instead of importing the Mudbox sculpted detail as maps I ended up importing the level 1 subdivision of my rocks as .obj files into Maya and re-unwrapping them. Simple silhouettes were all that I needed but it might have been faster to figure out how to combine my Mudbox map and Photoshop map for applying as one map onto my first boxes.



Paint Effects for Grass and Trees

Week 11

Using the stargazing scenario, we challenged ourselves to see if we could translate the style which we wanted into 3D. Sorcha and Aidan worked on the characters while Molly and I worked on the environment.

For the environment, I started by focusing on the foreground. I blocked out where the rocks would be and moved some vertices around on a plane until it resembled the shape of the ground in my painting. I figured that it would be good to try and match my painting as closely as possible as I had already made a lot of compositional decisions while painting it.

I tackled the grass next and discovered Paint Effects, as I discussed in my post Paint Effects for Stargazing Environment. I found that the direction of the grass followed the direction of the stroke so it was better to paint stokes towards the focal point for compositional flow. I experimented with making different shapes with the tube’s attributes until I made a suitable grass shape, length and elevation.

Grass painted from left to right with no planned flow:

Grass painted with flow towards the characters:

Simple colours with a directional light:

As I learned from Mastering Autodesk Maya 2016 I was unable to use light linking with paint effects. I could unlink the light from the ground though and use incandescence to match its colour to the shadow colour.


Maya software render

This seemed to work well enough for the rocks also until I needed to use displacement maps which I’ll talk about in a different post. I rendered the grass separately in Maya software renderer and composited a texture in After Effects.

After I had some form of usable grass I moved onto tackling the rocks and then the trees. For the trees, I similarly spent some time editing the shapes of Paint Effects tubes to make the appearance of evergreen trees.


Trial and Error

Once I had a tree shape which I liked I looked up how I could save these settings as my own custom brush. This is the closest way that I’ve found to make my own brushes but I would still like to be able to paint with my own geometry made from scratch.

To animate the trees I used the turbulence attribute similar to the grass. The main challenge here was trying to make the trees look like they were in the same wind as the grass but reacting differently/slower due to their weight.

Turbulence too fast:

Adjusting the turbulence attributes:

For adding texture in After Effects, I had thought that using a background shader to shade the rocks with no shadows would work to create an alpha channel but in the end I needed to convert the Paint Effects to polygons and use surface shaders in order to make selectable areas. Using what I had learned about in my blog post Alpha Channels, Masks and Mattes, I was able to use these white/rgb shaded renders of the grass and trees as mattes for a canvas texture which I had created in Photoshop.

This was the composited result:


I don’t like how flat the trees look so I would like to return and continue experimenting with making the light catch foliage in a suitable way.



Alpha Channels, Masks and Mattes

Week 11

Alec shared this tutorial with us for using rgb channels as mattes in Nuke.


I wondered if there was a similar method to use in After Effects and found this:

Ask DT: After Effects – How to Composite Together a RGB matte, or ID Pass

This method uses keying>colour key to key out a particular colour. I found that this did not work very well for masking my grass as the edge was not very accurate even after adjusting the ‘edge thin’.

I found that this method using the ‘shift channel’ effect was more accurate. Not only can the transparency be shifted to show only luminance/white but also to red, green or blue and then the selected area/alpha can be used as a matte for another layer.


How to key out black


While searching for information about using masks in After Effects I came across this article:

After Effects Help/Alpha channels, masks and mattes

I thought that these notes in particular were interesting:

“The term alpha channel technically refers to the fourth (A) channel in an RGBA image file, regardless of whether that channel is used for communicating transparency information. However, since that fourth channel is used so often to communicate transparency information, the terms alpha and transparency have become nearly synonymous in common usage. It’s important to remember, though, that this connection is essentially arbitrary. Some formats may use other channels for transparency information, and other formats may use the fourth channel for something other than transparency information.”

…”A matte is a layer (or any of its channels) that defines the transparent areas of that layer or another layer. White defines opaque areas, and black defines transparent areas. An alpha channel is often used as a matte, but you can use a matte other than the alpha channel if you have a channel or layer that defines the desired area of transparency better than the alpha channel does, or in cases where the source image doesn’t include an alpha channel.”

“…A mask in After Effects is a path that is used as a parameter to modify layer attributes, effects, and properties. The most common use of a mask is the modification of an alpha channel of a layer, which determines the transparency of the layer at each pixel.”

Paint Effects for Stargazing Environment

Week 10

I was just beginning to research how we could create the grass in our stargazing scene when I came across this method using paint effects. In this tutorial, Hermes demonstrates how you can simply paint clumps of grass with the stroke of your pen/mouse. These grass clumps can then easily be modified and animated by using the turbulence tab under the attributes. I will research more into how flexible this system is for creating our own style, particularly for adding elements that look like brush strokes, or on the opposite end of that, very flat and graphic.

Maya 2014 tutorial: Animate grass to react to wind

In order to research more into how Paint Effects can be used I looked through chapter 10 of this book:

Mastering Autodesk Maya 2016 

Screen Shot 05-01-16 at 01.45 PM.JPG

These were some of the questions which arose before or during my reading through the chapter.

Chapter 10 Paint Effects pg 419 – 471

What do I need to figure out from these chapters?

  • How do I make my own custom shape to paint with?
  • Can I shade these whatever way I want to? How can I make a custom grass shape and shade it the same colour? And then light it?
  • Do they look good with light rendered with Maya software?
  • How can I animate these with ‘turbulence’ to match the wind in the scene?
  • What surface will I paint these on? Will the ground be visible?
  • How can I shade and light the grass so that it only fluctuates between two colours when it blows in the wind. Dark grass that catches hard light. – light link only the grass, make the ground the same colour?
  • Do you need to cache the wind/turbulence animation? Will the animation be retained in history?

These are some notes which I took while reading. There are still some areas which I haven’t covered yet e.g. Sorcha was telling me about painting along curves to create hair. At least I know that it’s possible.


Painting on 3D objects pg 425

  • You can paint in any camera or through the paint effects window.
  • You can create a bumpy/organic surface by lofting a surface between two dynamic hair curves (explained in a different chapter).
  • Paint Effects can be used with pressure sensitivity on your stylus using the pressure mapping settings e.g. mapped to scale. I didn’t fully understand how to make this work at first so I searched online and found this video which helped:

Pluralsight Creative (2013) Top Tip: Using Pressure Sensitive Features Within Maya

  • Both nurbs and polygon objects can be painted on.
  • Make 3D objects “paintable”. Objects must be UV mapped in the 0 to 1 space. You can paint on a moving surface such as water. You can generate paint effects on a nurbs curve.

Understanding strokes

  • A stroke node and a transform node is created when you paint. The brush node is also connected to the strokes and retains a construction history.
  • Each stroke has its own brush node but you can edit brushes at the same time with brush sharing.
  • You may need to make changes in the node editor e.g. to change the type of curve controlling the stroke.
  • A different curve node is created depending on the type of surface which is painted on.

Designing Brushes

  • Paint effects is a development of L-systems; mathematical algorithms used to simulate living organisms.
  • Some brushes add shapes to the scene. Others work by affecting the appearance of geometry behind the brush. E.g. ‘erase’ paints black holes in the alpha channel.
  • Mesh strokes don’t render in Mental Ray. However, strokes can be converted to polygons.

Rendering Paint Effects

  • Light linking does not work with paint effects.

This article from Autodesk was helpful to load the Paint Effects shelf and add custom brushes to the shelf: Prepare to use Paint Effects.

Office Stress Part 02: Try Again

Week 10

I wasn’t happy with how my previous take on the ‘stressed scenario’ was working out so I started again with a composition in mind which would tell a story with both Julie and William as the focal point. Before, I think I had struggled too much to include the window for pathos and didn’t choose the most interesting camera angle. I think that it’s good to vary the camera position so that we can frame the scene from new perspectives e.g. maybe we’re the cat looking down from a shelf or maybe we’re a passerby looking through the window from outside. Clarity of story always takes priority of course. Feng Zhu has a helpful lecture on planning camera angle for purpose which I blogged about in FZD Camera Placement.

This time around, I blocked the scene out in Maya so that I could play more with the camera angle and focal length with a clearer result. Sometimes I get distracted by perspective problems in my planning sketches.

I had an idea of what I wanted from looking at Pascal Campion’s piece Doubt, blogged about in Stargazing: Possible Palettes, so I was quickly able to choose a camera angle and lay down where I wanted the light. I liked the idea of Julie bringing warm light from the doorway into the stressful environment of William’s cold office as he works late into the night. I haven’t finished yet but I plan to paint Julie so that she’s being helpful in some way like bringing a coffee or a blanket and I need to clearly convey how stressed William is. I’ve given myself a challenging perspective to draw figures in. I also need to ensure that I don’t make William’s office too neat like I did in the last one.