Eyeon:Manual/Tool Reference/3D/3D Shadow Controls

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Shadow Controls

The Enable Shadows checkbox should be selected if the light is to produce shadows. This defaults to selected.

Use this standard Color control to set the color of the shadow. This defaults to black (0, 0, 0).

The shadow Density determines how opaque the shadow will be. A density of 1.0 will produce a completely transparent shadow, whereas lower values make the shadow transparent.

The Shadow Map Size control determines the size of the bitmap used to create the shadow map. Larger values will produce more detailed shadow maps at the expense of memory and performance.

Shadow Map Proxy determines the size of the shadow map used for proxy and auto proxy calculations. A value of 0.5 would use a 50% shadow map.

Shadows are essentially textures applied to objects in the scene so there will occasionally be z-fighting, where the portions of the object that should be recieving the shadows render over top of the shadow instead. An example of Z-fighting is shown below.

Biasing works by adding a small depth offset to move the shadow away from the surface it is shadowing, eliminating the z-fighting. Too little bias and the objects can self-shadow themselves. Too much bias and the shadow can become separated from the surface.

Make adjustments to the Multiplicative Bias first, then fine tune the result using the Additive Bias control.

Normally, a RGBAZ shadowmap is used when rendering shadows. By enabling this option you are forcing the renderer to use a Z only shadowmap. This can result in significantly faster shadow rendering while using a fifth as much memory. The disadvantage is that you can no longer cast 'stained-glass' like shadows.

Soft edges in shadows are produced by filtering the shadowmap when it is sampled. Fusion has three separate filtering methods available when rendering shadows which produce different effects.

• None - Shadows will have a hard edge. No filtering of the shadowmap is done at all. The advantage of this method is that you only have to sample one pixel in the shadowmap so it is fast.

• Constant - Shadows edges will have a constant softness. A filter with a constant width is used when sampling the shadowmap. The size of the filter is controlled by adjusting the Constant Softness slider. Note that the larger you make the filter, the longer that it will take to render the shadows.

• Variable - The softness of shadow edges will grow the further away the shadow receiver is from the shadow caster. The variable softness is achieved by changing the size of the filter based on the distance between the receiver and caster. When this option is selected, the Softness Falloff, Min Softness and Max Softness sliders appear.

If the Softness is set to constant, then this slider will appear. It can be used to set the overall softness of the shadow.

The Softness Falloff slider appears when the Softness is set to variable. This slider controls how fast the softness of shadow edges grows with distance. To be more precise, it controls how fast the shadowmap filter size grows based upon the distance between shadow caster and receiver. Its affect is mediated by the values of the min and max softness sliders.

The Min Softness slider appears when the Softness is set to variable. This slider controls the Minimum Softness of the shadow. The closer the shadow is to the object casting the shadow, the sharper it will be up to the limit set by this slider.

The Max Softness slider appears when the Softness is set to variable. This slider controls the Maximum Softness of the shadow. The further the shadow is from the object casting the shadow, the softer it will be up to the limit set by this slider.