Illustrations/Digital Models: Clay Style Rendering Tutorial

Discussion in 'Tutorials and How Tos' started by Venksta, Aug 22, 2009.

Thread Status:
Not open for further replies.
  1. Venksta

    Venksta Render Project Creations TFW2005 Supporter

    Joined:
    Jul 1, 2002
    Posts:
    6,504
    News Credits:
    35
    Trophy Points:
    367
    Likes:
    +1,564
    This tutorial is to show one way to create a “Clay” style render in your preferred 3d program. However, those who have a 3d program that has Mental Ray built in will find this easier to follow along, especially for the last part. I use Softimage XSI to do my 3D work in. This tutorial will be shown in Softimage XSI 6.5. However, the basic method can be applied to your program of choice, as long as you know where the similar settings or tools are located. It is required for you to have basic knowledge of the program you use, that way, you can locate tools to help do this tutorial. If you have any questions, feel free to PM me.

    This method of the clay style render is only one of several ways to do this. I also feel this will be easier to do in other programs, as it uses a basic setup. There are things you can play around with, like color and lighting. But I recommend you to follow what I instruct below, so you have an idea of the tutorial and setup better, before playing around with it.


    Clay Rendering

    Part 1: Creating a scene to render

    Part 2: Adjusting your model’s material/shader

    Part 3: Building the sky dome and ground

    Part 4: Lighting

    Part 5: Rendering


    Part 1 – Creating a scene to render

    So to make a render in the Clay style, we need a model first. Below is a screenshot showing the model I’ll be using in this render, which is of Classics Optimus Prime. You can use anything for this tutorial, a simple cube, or your own Transformer model. Once you have your model loaded, you can pose them, if you want.

    Part 2 – Adjusting your model’s material/shader

    Now that you have your model ready to go, the main adjustment you need to make is to the material. Give the entire model a “matt” material that has no specular to it. If Phong is a glossy material, then you want something that has no gloss to it. In XSI, my preferred material is called a Lambert. For the color, pick a nice grey. Make sure it isn’t tinted by any other color. Then apply this to your entire model. A “matt” type of material works the best for a clay style render.

    If your model has any transparent parts, like a window, you can give it a Phong material. Since transparent parts are only made by glass or clear plastics, a phong material works well with the rest of the model being a matt material. It is best not to tint it any color, to help create the over all clay look. Give it a mid range transparency value. You can add hint of reflection to it if you want, but it just means the render time would be increased some what.

    [​IMG]

    Part 3: Building the sky dome and ground

    Now we need to build a dome to create the blue filler light for the clay rendering. Create a sphere object, and give it enough subdivisions so its nice and round. Then scale it so it is very big compared to your model(compare to screen shot below). We only need the upper half of the sphere. So delete the bottom half of the sphere. After that, we need to invert what is now the dome, so that the polygons properly show up from inside. In your program, once you select the polygons, you should have an option that can invert them.

    [​IMG]

    Once you have the dome modeled, we need to give it a “Constant” material. This type of material color stays, constant, as it is not affected by any lighting. So if I pick a bright red color, it will always appear that very color, even if there is no lighting in the scene. For the dome, pick a bluish-grey color. The dome color will affect the light and darkness of the render. So later, you can come back and try different shades or colors. For now, pick a color that is close to the screen shot below.

    [​IMG]

    Next, we need a ground. There are two types of grounds you can go with. The quick way, is to just add a grid/flat polygon, which extends pass the dome along the X and Z axis.

    The second is to model a L shape booth, which mimics something you would find at a photo shoot. Basically a grid, where the back curves up. This will look nicer for your render. To model this, create a grid/flat polygon. Then select the rear edges/line, and extrude them twice, and move them apart to look like the screenshot below. The last extrusion should move the edge/line straight up. For the scale of this object, it should not be bigger than the dome. But big enough, so it stretches pass the camera’s view. You can rotate or move this when needed for your camera angles.

    [​IMG]

    The next step for the booth is optional. If you know how to make an object smooth by adding subdivision, give the booth a subdivision by up to a value of 2. It will make the “elbow” part of the booth look nice and smooth for the render. Screenshot below to show you the difference.

    [​IMG]

    Once you have a ground, give it a “matt” material/shader. I usually pick a bluish-grey color, something similar to the dome’s color, but a different shade of blue, and a bit lighter.

    Part 4: Lighting


    Next, we add a light. For this type of setup, a Point/Omni light is the best. It has a limited range, however, it shoots rays of light in all directions from it’s origin. For the lights color, plain white, or a slight tint of yellow/orange is ok. You can place this light anywhere inside the dome. Closer to the model is best, but give it a good distance for space. My personal preference for the light’s position is top left , in front of the model. As if it were the sun. This light will control the intensity of the renders brightness, along with the Dome’s color. So for intensity, I usually go for value of 0.5 to 0.6, in a 0.0 to 1.0 scale. There will be a soft shadow created later, when we turn on a setting, but I still like to give the main light its own shadow, which is nice and dark. You can play with the value to your liking.

    [​IMG]



    Part 5: Rendering

    This next part is crucial. For all of the above to work, we need to turn on Final Gathering. As far as I know, Softimage, Maya and Max all use Mental Ray for its rendering. Mental Ray has a feature called Final Gathering. It basically lets rays of light bounce off everything in the scene, to create a Global Illumination type of look, similar to real life. At this time, if you render, the only light in the render will be come from the Point light. But if we turn on Final Gathering, the Point light’s rays will hit the dome, which in turn bounce off and hit the model from other directions, so it isn’t completely dark.

    First, go into your render settings, and look at your Aliasing settings. The Aliasing setting is very important, especially if you want Final Gathering to be worth rendering. For my final renders, I always go with Max 2 and Minimum 2. If you want to test render first, you can go lower. But for a final render, 2 and 2 is great, or 1 and 1.

    Next, look for the Final Gathering tab/menu in the render settings. The screenshot below shows what it looks like in Softimage XSI 6.5. For myself, I need to check “Enable” to turn Final Gathering on, and be able to see all the options and settings for it.

    [​IMG]

    As for the settings to change, if you have the option for “Preview” under “Visualize”, check that. This option starts the render off with a rough look, followed by the full render. This will help check the lighting, as it does a rough render first(seen below), and lets you see how the lighting looks, in case you feel any changes are needed. For example, if the point light is too high or too low.

    [​IMG]

    At this point, if you like the preview, you can let it finish rendering. Or you can make changes. Now, if you wanted, you can play with the Final Gathering settings. You will find the render time can increase. But the main settings I recommend increasing are the following:

    Number of Rays: 300 or more
    Points: 25 or more
    Max Radius: 30 or more

    The changes help make the image more refined and can help pop out details better. However, some people might feel the increase in render time is not worth it. Below are two renders. The one on the left is rendered at default Final Gathering settings. The one on the right is rendered with increased settings.

    [​IMG]

    That’s it for the tutorial. Hope you were able to follow along and render your model in the clay look. If you feel you got the hang of it, try playing around with the colors and lighting. Try placing the Point light behind or to the opposite side of the camera, like in the example below. And you can brighten the model up by picking a lighter color for the dome's material. You can also use the light setup to render your model in full color as well.

    [​IMG]

    [​IMG]


    It'll be cool to see your models in this type of render. Btw, once you have the light, dome, and booth done, you can just save them off as a model, and easily import them into any scene. The only thing you would have to do then is to just turn on final gathering, and delete any other default light in the scene.

    Thanks guys. :) 
     

    Attached Files:

    Last edited by a moderator: Oct 13, 2009
Thread Status:
Not open for further replies.