AECbytes Tips and Tricks Issue
#36 (November 20, 2008)
Harnessing the Composite Map in 3ds Max Design 2009
Book & Video Author
Back in August 2007, I wrote AECbytes Tips and Tricks Issue #21, Compositing 3ds Max 9 Renderings in Photoshop CS3, which was about taking renderings generated in 3ds Max and combining them in Photoshop. This issue is about a different but somewhat analogous process—compositing multiple "Photoshop" image inputs inside a single material in 3ds Max. The composite map has been around for many years to aid in designing complex 3ds Max materials, but the reason I'm excited about it now is that it's been completely revamped in 3ds Max Design 2009.
The new composite map is like having (and my apologies to Adobe for making this comparison) a basic version of "Photoshop" inside 3ds Max. Well, it's not really Photoshop, but the composite map does support layers, opacities, blend modes, masks, and even color correction, so it's amazingly powerful. Obviously 3ds Max Design 2009's composite map is no substitute for Photoshop (you need them both), but it does make designing complex materials in 3ds Max that much easier and convenient. You can follow along with this tutorial by downloading the sample files here. I'm assuming you are experienced using 3ds Max's material editor for this tutorial.
Creating Geometry and Assigning Mapping Coordinates
Launch 3ds Max Design 2009 and create a box. Switch to the Modify tab of the command panel and adjust Box01's parameters to Length 0'8", Width 16'0", and Height 8'0". Move the box to the origin to center it on the grid if you like things nice and neat. We will design a complex material and map it on this simple wall to give you a taste of what you can do with the composite map in 3ds Max Design 2009.
As we are planning to use bitmaps in the material we will design for this box, it is necessary to have mapping coordinates assigned to the box. Leaving Generate Mapping Coords checked assigns box type mapping automatically, so we won't need an explicit UVW Map modifier. Uncheck Real-World Map Size in Box01's parameters to make complex map tiling much more straightforward.
Designing a Material using the Composite Map
Press M to open the Material Editor and click on the upper left sample slot. Change the material type to Standard if it's not already. Set the default Scanline Renderer as the production renderer in the Render Scene dialog box if necessary. The composite map will work with other renderers and/or material types, but I'd like to keep things as simple as possible to focus on the composite map. Assign the material to the box you created earlier. Change the name of the material to Composite Wall.
Click the blank map button next to the Diffuse color swatch in the Blinn Basic Parameters rollout in the Material Editor. Choose Composite in the Material/Map Browser dialog box that appears.
The new interface of the composite map requires some explanation. In previous versions of 3ds Max, the composite map had a very simple interface with just two buttons. In the past, two maps could be composited using their alpha channels. Now any number of maps can be combined via layers & masks that work very much like their counterparts in Photoshop. The interface shows only one layer at the start: Layer 1.
Notice the two sets of identical looking buttons—those on the left are for the layer map and those on the right are for the layer mask (which is optional). The layer and its mask each have visibility toggles in the form of the two-eyed buttons. The drop down menu lists layer blend modes and opacity is on a spinner.
Click the left None button to assign a layer map. Choose Bitmap in the Material/Map Browser dialog box and select Concrete.Cast-In-Place.Formwork.Holes.jpg (a 3ds Max sample file from the ArchMat library). In the Coordinates rollout of the Bitmap, uncheck Real-World Scale. Set U and V Tiling to 2.0. Click the Show Map in Viewport toggle (blue and white checkered cube icon) and turn off Show End Result (adjacent button on the right) so you can see the flat bitmap in the sample slot.
Click the Go to Parent button to return to the level of the Composite map in the Material Editor. Click the Create New Layer button to add Layer 2. Click Layer 2's leftmost None button to map it. Select Bitmap in the Material/Map Browser and select Finishes.Plaster.Stucco.Fine.Brown.jpg. Uncheck Real-World Scale and set U and V tiling to 2.0. Click the Go to Parent button again.
In order to hide a portion of the stucco of Layer 2 (and thus reveal some of the concrete underneath) you will mask Layer 2. Click Layer 2's rightmost None button and select Gradient Ramp in the Material/Map Browser that appears.
In the Coordinates rollout of the Gradient Ramp, uncheck Use Real-World Scale (as always) and set U and V tiling to 0.5. Change the W angle to 90 to rotate the gradient on the wall so that it's running up and down.
Scroll down in the Material Editor to the Gradient Ramp Parameters rollout and double click the middle flag to open the color picker. Set its color to white. Click to the left of the flag you just altered to add another flag. Double click the new flag and set its color to black in the color picker that appears. Drag both middle flags to the approximate positions as shown below. Now the gradient fades more quickly from black to white and the flag positions control exactly where this happens on the wall. Click the Show Map in Viewport toggle to visualize this in the viewport.
Add a little noise to the gradient ramp to mix up the transition line. In the Noise group, set Amount to 0.15 and Size to 0.5.
Click Go to Parent to return to the Composite map level in the Material Editor. You should now see layer and mask thumbnails as shown below. Toggle the Show Map in Viewport button to see what's happening at this level in the viewport. Stucco appears at the bottom of the concrete wall as moderated by the noisy gradient ramp map. To globally fade out the stucco slightly, change Layer 2's blend mode to Overlay.
At this point, I'm distracted by the color of the tan stucco on the gray concrete because it looks just like someone slathered stucco on this beautiful concrete wall. To give the concrete a weathered look instead, try color correcting Layer 2's layer map. Click the leftmost Color Correction button on Layer 2. The stucco bitmap is automatically nested inside the new Color Correction map. Drag the Saturation and Brightness sliders a short distance to the left to gray and darken the stucco.
For more fun, let's add one more layer to the Composite map. Click the Go to Parent button and add Layer 3. Map Layer 3's leftmost None button with a Bitmap and select aecbytes.png. It's some stencil text I created in Photoshop. Notice that the image has a white background and png images don't support alpha channels (which was how the composite map worked in previous versions of 3ds Max).
In the Coordinates rollout of the Bitmap you just selected, uncheck Real-World Scale and set Tiling to 1.0 in U and V. Uncheck both U and V tile checkboxes so the bitmap doesn't repeat and acts like a decal. Change the W angle slightly to add interest (here I used -14.0). Move the bitmap up slightly by setting V offset to 0.2.
Click Go to Parent to return to the level of the Composite map. Right now, the white background of Layer 3 obscures the other layers. Change Layer 3's blend mode to Multiply to remedy this situation. Tone the text image down by reducing Layer 3's Opacity to 70.0. Tip: you can change layer order within the Composite map by dragging Layer rollouts around. Layers that are higher in the layer stack are composited on top of underlying layers, just like in Photoshop. This is the opposite stacking order as compared to how the modifier stack works in 3ds Max.
Click the Material/Map Navigator button on the right edge of the Material Editor to visualize the structure of the complex material you've just designed. Note that you've only mapped the Diffuse Color channel up to this point, so this is still an incomplete material. Ttry mapping the Bump channel on your own for added realism.
Click the Quick Render button on the main toolbar to see what the composite material looks like mapped and rendered on the wall. This is just a taste of the complex materials you can make by harnessing the power of layers within the new composite map in 3ds Max Design 2009. Enjoy.
About the Author
Scott Onstott has a degree in architecture from UC Berkeley and worked in several prominent architecture, engineering, and interiors firms in San Francisco. In addition, he taught AEC software to thousands of students at several Bay Area universities.
Scott has written and edited scores of books, magazine articles, and video tutorials. He can be reached via ScottOnstott.com.
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