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Adding Shadows and Radiosity

Page 5.

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The default lighting in Max does not cast shadows, so in order to make our Ball cast a shadow onto the floor, we need to add a light.

• Create>Lights>Omni

• Click in a View Port

• Position the light so that it's above the ball, in front of it, and to the right hand side:

•  Use your eye to judge where it should be.

• With the light selected, go to the Modify Panel

• Check the Cast Shadows Check Box.

• Increase the Multiplier Value to 1.12

Try a test render (still image, 320X240, un-check "save file")

Doesn't look great  does it? This is because of the lack of Radiosity in the scene.

Radiosity:

Radiosity is the term used to describe reflected light in a scene. In the real world, just about every object reflects light. For example, in the average room, the majority of the light is bounced off the walls. In 3D Studio Max however, nothing reflects light.

Radiosity Render Engines do exist, but they cost a lot of money, as it take some serious processing power to calculate every ray of light and its path as it bounces off of various surfaces with different radiosity values!

However, we can simulate Radiosity through the careful placement of some extra lights.

• Create another Omni Light.

• This omni light is going to simulate the light reflected back off of our box, so place it near the box's surface. Because the Camera is not moving in this scene, we only need to worry how the image looks from one angle. If the camera was moving, we would have to be much more thorough with the placement of our lights.

• Try another test render.

It looks better, but it's still not right.

Colour Bleeding:

This is because when light bounces off a surface, it inherits colour from that surface. This process is referred to as Colour Bleeding. 

Also, our second light should not affect the box, as it is the box that is supposed to be emitting it! So, the final stage is to alter the colour of our second light and exclude the box.

• Select your second light.

• Go to the Modify Panel.

• Change the Multiplier Value to 0.5

• Click on the Colour Swatch, and change the colour to match the colour of your box, only lighter.

• Click on Exclude.

• Choose your Box from the list of objects that appears, and then click on the right facing arrows to move it to the Exclude list.

• Click OK.

• Now try another test render. You should have something like this:

If your wondering why my Box looks better than yours, it's because I've used a Chamfer Box from the Extended Primitives. Using a Chamfer Box enables you to Bevel the edges slightly, making them catch the light. This makes the box look more realistic.

So, try Rendering your whole animation with your new lights and see how it looks. Try moving the lights around, adjusting there values, adding more lights and more objects, and see what you can come up with.