MAXON Computer Cinema 4D Tutorials: Creating Velvet

Tips & Techniques - Smells Like Almonds

Smells Like Almonds:
Creating Velvet
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Project Works with:
XL Requires:
Version 7.1+

This tutorial will demonstrate how to use SLA to create an anisotropic material such asvelvet.

Step 1: Setting up your scene.

Open up a new scene and bring in a model of something you would like to apply a velvet texture to. If you don’t have a model, make something quickly like a skirt, or use the dress included in this project. Whatever you use, make sure it has a nice fold in it somewhere so you can see how the material will affect the object. Next set up your lighting, which is key to getting good results. Velvet is a very dark material, so you may have to over-light your scene while you work on the construction of your material. Create a New Material in the Materials Manager (File=>New Material). Rename this material 'Velvet'.

Now bring in some reference material. Included in the project is a .jpg image (velvetref.jpg), which is a picture of a red velvet shirt, and a close-up shot of its specular highlight. Open the image in CINEMA's Picture Viewer (File=>Open).

velvetref.jpg.

Having a reference picture will help you so you can quickly match your colors and textures. It’s a good idea to always have some reference material when you are creating a material.

Step 2: Creating the color.

The color for velvet is fairly simple, it’s just a noise channel with two closely related reds. The reds are actually very dark, that is the nature of velvet. Most of the color you will see is going to be based on your diffusion, specularity, and most importantly, your lighting. So in the image field for your Color place a bhodiNUT 2D Noise (Right Arrow->bhodiNUT Channel=>bhodiNUT 2D Noise).

Materials.

Click Edit to open up the settings for your noise. Change the Mode to Plane, and the Type to VL Noise. Next change the Global Scale of the noise to 20%. Next set your colors. For Color 1 use a red with the following values R:85 G:0 B:0. For Color 2 use a slightly darker red with the values R:75 G:0 B:10. Click OK.

Step 3: Creating the diffusion.

Next go over to the Diffusion tab and turn it on. You will use this part of the material to add your light and dark areas. For this you will have to blend 2 Noise channels, so create a Fusion shader (Right Arrow=>bhodiNUT Channel=>bhodiNUT Fusion).

Click Edit to open up the settings for your Fusion. Next, place a 2D Noise in both the Blend and Base Channels of your Fusion.

First edit the settings for your Blend Channel Noise. Change the Mode to Plane, and leave the Type at the default Noise. Next turn the Global Scale down to 5%, and the Contrast down to –20%. This Channel is going to enhance the fuzz of your fabric. Now go into your Base Channel Noise. Change the Mode to Plane, and the Type to Turbulence. Turn up your Global Scale to 250%, and set the Contrast down to –40%. This channel will define your light and dark areas of your fabric. Click OK.

Now you are in your Fusion dialog and you have to blend your two noises together. Leave the Mode at normal, and set the Amount to 20%. If your dark and light areas are too noticeable then try turning down the Contrast of your Turbulence even more.

Note: If your velvet is too dark later on, you can mix your diffuse with white in the Diffuse tab's main options.

Step 4: Creating the Bump map.

Since your Bump is going to be a Fusion of two Noise channels just like your Diffusion, all you need to do is copy the Fusion from your Diffusion and paste it into your Bump channel's Image field. Now edit the two Noise channels starting with your Blend Channel. Change the Type to FBM Noise, with a Global Scale of 50%. Also bring the Contrast back to 0%.

Click OK and then edit your Base Channel Noise. Change the Type to Random, and set the Global Scale back to 100%. Next change the Contrast to –65%. Click OK. In your Fusion dialog bring the Contrast up to 30%. Now you have a very rough image that will really help break up the specular highlight so your fabric doesn’t look so shiny. Click OK, and set your Bump Strength to 15%, and make sure it is turned on (checked) in your Material dialog.

Step 5: Specularity.

Up to this point all you have done is given the material its color. The hardest part is defining it’s specularity, which is what will make it look like cloth. It takes a lot of tweaking to get nice highlights that blend well with the material, without looking like plastic.

On the right side of your reference material there is a zoomed in picture of the velvet’s specular highlight. Use your mouse and keyboard to zoom in on the image on the right, you are going to match the highlights to your geometry’s texture. So the first thing you need to do is change your Illumination Model. Go to your Illumination channel in the Velvet material and change the Model from Phong to Oren-Nayer.

Now you have another global control over the roughness of your material. Set the Roughness here to 75%. Click OK.

Now go over to your Specular channel and set the Mode to Plastic. Use a Width of 30%, a Height of 50%, and a Falloff of –3%. This will help keep your highlights sharp.

Note: In the Specular channel, you have control over where the higlights will be, the Specular Color will give you control over the highlight's shape and color.

Step 6: Specular Color.

Now you will use a bhodiNUT Lumas in your Specular Color channel. With Lumas you can have more than one specular highlight, so you can use one for the bright red highlights, and another one to shade the entire model and give it more of a 3D quality. You will also turn on Anisotrophy, which will give you a lot more control over the shape of your highlight, so you can have your highlights run down the folds of your clothing material. So in the Image field of your Specular Color channel, place a Lumas shader (Right Arrow=>bhodiNUT Channel=>bhodiNUT Lumas).

Click Edit to open up its settings. Turn on Diffuse, Specular 1, Specular 2, and Anisotrophy. Then go into your Diffuse settings. With the color slider, give the R value 35%, and O% for G and B. Give the Brightness a value of 30%. In your Attribute options, set the Algorithm to Oren-Nayer, the Roughness to 90%, the Illumination to 90%, and the Contrast to 25%.

Now go to your Specular 1 tab. This is going to control the bright red highlight, just like the one in your reference window. So start by giving it a bright red color. Bring the color sliders up to R:98% G:15% B:18%, then bring the Brightness up to 45%. You want this highlight to be small but noticeable, so turn the Intensity up to 100%, but keep the Size down to 0.5%. Make sure Contrast and Glare are set to 0%, and your Falloff is at 100%.

Now go over to your Specular 2 tab. Here is where you will give an overall highlight to the material to help create some depth. Use the same color as Specular 1, but make it a bit darker. The values for the color are R:98% G:15% B:18%, with a Brightness of 25%. Make the Intensity 25% and the Size 60%. Again, set your Contrast and Glare to 0%, and your Falloff to 100%.

The next thing you need to do is adjust the settings for the Anisotrophy. Set your Scratch Projection to Auto-Planar. Next adjust the settings for your Anisotropic Specular Roughness. Turn the X Roughness up to 395%, and the Y Roughness up to 660%. Make sure it affects both Specular 1 and 2. In the Scratch Attributes, set the Amplitude to 95%, set the Scale to 75%, the Length to 200%, and the Attenuation to 100%. Again, make sure it affects both of your specular highlights. Click OK and you are finished creating the velvet.

Step 7: Adding a Fresnel Effect.

Your dress is almost finished, but it still seems a little too flat. It needs some soft secondary highlights, specifically aound the edges. By adding a Fresnel to your Diffusion channel, you can get the subtle effect of these highlights where you want them. Fresnel effects your material based on your geometry's normals in relation to the camera. So you can brighten areas of your dress facing the camera. This will enhance the folds in the dress by making them stand out more. It will also help your dress stand out from the background by giving it a nice edge.

Switch over to your Diffusion channel, and copy the Fusion channel that you have for it (Right Arrow=>Copy Channel). Then press Edit to open up its settings, and Paste it into your Base Channel (Right Arrow=>Paste Channel). Next Add a Fresnel to your Blend Channel (Right Arrow=>bhodiNUT Channel=>bhodiNUT Fresnel).

Then click Edit to open up its settings.

The settings are fairly simple, remove the gray color from the middle of your gradient, then slide the black color over to around 80%.

After you've finished, click OK.

Now you have to blend the Fresnel channel with your existing Diffusion channel. First change the Preview Mode to Sphere, this will help you visualize the impact your settings will have on your material. Set the Blend Mode to Screen and set the Value to 65%. You can adjust this slider to increase or decrease the amount of your edge highlights.

If you still want to brighten up the highlights around the edges, copy your Fresnel and paste it in your Luminance channel. Then change the white color to a very dark grey, you don't want it to be too bright.

Remember that lighting is going to play a very important role in your final render, and depending on your object's shape, you might have to adjust the Specular highlights in your Lumas channel. If you have the Dynamics plugin you can add soft springs to your geometry to get a realistic cloth simulation that would work great with this material. Have Fun.