578 Part IV Materials and Maps

Figure 20-14: A dolphin over the water with applied materials

Using External Tools

Several external tools can be valuable when you create material textures. These tools can include an image editing program like Photoshop, a digital camera or camcorder, and a scanner. With these tools, you can create or capture images that can be applied as maps to a material using the map channels.

Once the image is created or captured, you can apply it to a material by clicking a map shortcut button or by selecting a map in the Maps rollout. This opens the Material/Map Browser, where you can select the Bitmap map type and load the image file from the file dialog box that appears.

Creating material textures using Photoshop

When you begin creating texture images, Photoshop will become your best friend. Using Photoshop’s filters enables you to quickly create a huge variety of textures that will add life and realism to your textures.

Table 20-1 is a recipe book of several common textures that you can create in Photoshop. The table provides only a quick sampling of some simple textures. Many other features and effects are possible with Photoshop.

Chapter 20 Creating Simple Materials 579

Table 20-1: Photoshop Texture Recipes

	Texture	Technique	Create in Photoshop	Apply in Max as
		Faded color	Decrease image	Diffuse map
			saturation value
			(Image Adjustments
			Hue/Saturation) by
			20-30%.
		Surface scratches	Apply Chalk & Charcoal	Bump map
			filter (Filter Sketch
			Chalk & Charcoal) with
			a Stroke Pressure of 2,
			to a blank white image,
			then apply the Film Grain
			(Filter Artistic
			Film Grain) filter with
			maximum Grain and
			Intensity.

Adding stains	Use the Dodge and Burn
to fabric	tools to add stains to a
	fabric bitmap.
Surface relief	Apply Dark Strokes filter
texture	(Filter Brush Strokes
	Dark Strokes) to a texture
	bitmap, save image as a
	separate bump image.

Diffuse map

Diffuse map (original texture), Bump map (Dark Strokes version)

Planar hair	Apply the Fibers filter	Diffuse, Bump, and
	(Filter Render Fibers).	Specular maps
Clouds or fog	Apply the Clouds filter	Diffuse map
background	(Filter Render Clouds).
Nebula or	Apply the Difference	Diffuse map
plasma cloud	Clouds filter (Filter
	Render Difference
	Clouds). Then, switch
	black and white color
	positions and apply the
	Difference Clouds
	filter again.

Continued

580 Part IV Materials and Maps

Table 20-1 (continued)

	Texture	Technique	Create in Photoshop	Apply in Max as
		Rock wall	Apply the Clouds filter	Diffuse and Bump maps
			(Filter Render Clouds).
			Then, apply the Bas
			Relief (Filter Sketch
			Bas Relief) filter.
		Burlap sack	Apply the Add Noise filter	Diffuse and Bump maps
			(Filter Noise Add
			Noise) followed by the
			Texturizer filter (Filter
			Texture Texturizer) with
			the Burlap setting.
		Tile floor	Apply the Add Noise filter	Diffuse map
			(Filter Noise Add
			Noise) followed by the
			Stained Glass filter
			(Filter Texture
			Stained Glass).
		Brushed metal	Apply the Add Noise filter	Diffuse and Bump maps
			(Filter Noise Add
			Noise) followed by the
			Angled Strokes filter
			(Filter Brush Strokes
			Angled Strokes).
		Frosted glass	Apply the Clouds filter	Diffuse map
			(Filter Render Clouds),
			then apply the Glass
			(Filter Distort Glass)
			filter and select the
			Frosted option.
		Pumice stone	Apply the Add Noise filter	Diffuse and Bump maps
			(Filter Noise Add
			Noise) followed by the
			Chalk & Charcoal filter
			(Filter Sketch
			Chalk & Charcoal).
		Planet islands	Apply the Difference	Diffuse and Shininess maps
			Clouds filter (Filter
			Render Difference
			Clouds), then apply the
			Note Paper (Filter
			Sketch Note Paper) filter.

Chapter 20 Creating Simple Materials 581

	Texture	Technique	Create in Photoshop	Apply in Max as
		Netting	Apply the Mosaic Tiles	Diffuse and Opacity maps
			filter (Filter Texture
			Mosaic Tiles) followed by
			the Stamp (Filter
			Sketch Stamp) filter.
		Leopard skin	Apply the Grain filter	Diffuse and Opacity maps
			(Filter Texture Grain)
			with the Clumped option
			followed by the Poster
			Edges (Filter Artistic
			Poster Edges) filter applied
			twice.

Capturing digital images

Digital cameras and camcorders are inexpensive enough that they really are a necessary item when creating material textures. Although Photoshop can be used to create many unique and interesting textures, a digital image of a riverbed stones will be much more realistic than anything that can be created with Photoshop. The world is full of interesting textures that can be used as textures.

Avoiding specular highlights

Nothing can ruin a good texture taken with a digital camera faster than the camera’s flash. Taking a picture of a highly reflective surface like the surface of a table can reflect back to the camera, thereby ruining the texture.

There are several ways to counter this. One is to block the flash and make sure there is enough ambient light to capture the texture. Taking pictures outside can help with this because they don’t need the flash. Another technique is to take the image at an angle, but this might skew the texture. A third technique is to take the image and then to crop away the highlights that are unwanted.

Adjusting brightness

Digital images that are taken with a digital camera are typically pre-lit, meaning that they already have a already have light source lighting them. When these pre-lit images are added to a Max scene that includes lights, the image gets a double dose of light that will typically wash out the images.

You can remedy this problem by adjusting the brightness of the image prior to loading it into Max. For images taken in normal indoor light, you’ll want to decrease the brightness value by 10–20%. For outdoor scenes in full sunlight, you may want to decrease the brightness even more.

You can find the Brightness/Contrast control in Photoshop in the Image Adjustments Brightness/Contrast menu.

582 Part IV Materials and Maps

Scanning images

In addition to taking digital images with a digital camera, you can scan images from other sources. For example, the maple leaf that was modeled using patches in Chapter 15 was scanned from a real leaf found in my yard.

Caution	Most magazine and book images are copyrighted and cannot be scanned and used without
	permission.

Tutorial: Creating a fishing net

Some modeling tasks can be solved more easily with a material than with geometry changes. A fishing net is a good example. Using geometry to create the holes in the net would be tricky, but a simple Opacity map makes this complex modeling task easy.

To create a fishing net, follow these steps:

1.Before working in Max, create the needed texture in Photoshop. In Photoshop, select File New, enter the dimensions of 512 pixels×512 pixels in the New dialog box, and click Ok to create a new image file.

2.Select the Filter Texture Mosaic Tiles menu command to apply the Mosaic Tiles filter. Set the Tile Size to 30 and the Grout Width to 3 and click the OK button. Then select the Filter Sketch Stamp menu command to apply the Stamp filter with a Light/Dark Balance value of 49 and a Smooth value of 50.

3.Use the File Save As menu command and save the file as Netting.tif. A copy of this file is available in the Chapter 20 directory on the CD-ROM.

4.Open the Fish net.max file from the Chapter 20 directory on the CD-ROM. This file includes a fishing net model created by stretching half a sphere with the Shell modifier applied.

5.Select the Rendering Material Editor menu command (or press the M key) to open the Material Editor and select the first sample slot. Name the material net.

6.Click the map shortcut to the right of the Opacity value in the Blinn Basic Parameters rollout and double-click the Bitmap map type. This opens a file dialog box where you can select the netting texture. Then drag the material from its sample slot to the net object in the viewports.

7.If you were to render the viewport, the net would look rather funny because the black lines are transparent instead of the white spaces. To fix this, open the Output rollout and enable the Invert option. This inverts the texture image.

Note	Although you can enable the Show Map in Viewport button in the Material Editor, the trans-
	parency is not displayed until you render the scene.

Figure 20-15 shows the rendered net.