Varying the fur density by painting attributes

Note

This tutorial is a detailed look into what goes on at the network level. An automatic way to create the same effect is to use the Paint Fur Density tool on the shelf.

Varying the fur density will allow you to determine which areas have dense clumps of fur as well as areas that have relatively thin coverage. This tutorial is a continuation of Basic fur setup and Using guide hairs.

Note

The fur in the screen captures has color that was created in Changing the color of the fur using the color attribute.

You can do this tutorial without completing the Using guide hairs and Changing the color of the fur using the color attribute tutorials. This example uses colored fur for better visualization in the viewport.

  1. Set the Density parameter on the Fur SOP that you created in Basic fur setup to 1.

    This will leave you with very few guide hairs.

  2. Insert an AttribCreate node before the SKIN_OUT node.

  3. Change the Name parameter to furdensity and increase the Value parameter to 10 in the parameter editor of the AttribCreate node.

    This will leave you with a thicker patch of hair.

  4. Insert a Paint node between the new AttribCreate node and the SKIN_OUT node.

    You can do this by selecting the connecting wire, pressing Tab , and typing paint. The Paint SOP allows you to paint attributes.

  5. Turn on the Override Color parameter and change Cd to furdensity.

  6. In the scene, click and drag your mouse over the grid to paint it.

    Brushing with will make fur less dense, and will make fur thicker.

    For more information, see the brush tools help.

    Note

    You can change the Radius of your brush by holding ⇧ Shift + and dragging or by changing the value in the Operation Controls toolbar. You can also alter the Opacity to make each stroke less intense.

  7. Click in the viewport and choose Smooth to change the function to blend between the black and white areas.

    This screen capture displays the two new nodes you must create for this tutorial.

  8. Change the Value of the furdensity AttribCreate node from 10 to 200.

  9. Turn on the display flag in the Fur SOP to see the varying amounts of fur.

Remember, the Fur SOP should only be used for visualization in the viewport. In order to render, it is highly recommended that you use a fur procedural shader, which will delay the generation of fur until render time. For more information on setting this up, see Basic fur setup.

You can also control the fur density using a texture map.