Draw Draft Analysis

Draw Draft Analysis

Analyze draft angles within your model surfaces.

Draw Draft Analysis displays the draft angles of a model for mold making.
Based on a chosen ‘pull direction,’ this feature displays whether the draft angles will allow you to remove a model from the mold, and identify surfaces that may require use of ZBrush model tools to make corrections to any problematic surface angles with real time analysis updates.


How Draw Draft Analysis Works

When Draw Draft Analysis is turned ON, ZBrush analyzes the draft angles of the visible SubTool and establishes a pull direction based on the current camera position.
You have the option to reposition the model by use of the camera and/or gizmo3D and then select a new pull direction. Selecting a pull direction will lock the draft angles into place, allowing you to then rotate the model freely so that you can look for any prob­lematic surfaces.

2020_04
An example model being viewed in Draw Draft Analysis Mode

Once the pull direction is established, the model will be viewed in 3 primary colors: Green, Red, and Yellow.

    • GREEN – Good along the positive vector.
    • YELLOW – Good along the negative vector.
    • RED – Bad along either vector.

Draw Draft Analysis Functions

Draft Angle

This slider adjusts the draft angle relative to the camera view. When the Draft Angle slider has been adjusted, the SetDir button must be pressed to display draft angle chang­es from the pull direction.

SetDir

The set direction button updates the pull direction of the draft angle relative to the camera.

InvDir

The inverse direction button reverses the current pull direction/draft angle.


Draw Draft Analysis in Action

2020_05

This example demonstrates a coin that will be output to generate a mold from its surface. Using Draft Analysis, follow these steps to identify any problematic angles that require correction before output.
1. Rotate and position the model in top orthographic view using LMB/RMB camera navigation. (*Press the Shift key while rotating to lock to orthographic top view of the coin.)

2. Turn on Transform >> Draw Draft Analysis. ZBrush will capture the “pull direc­tion” based on this orthographic camera position.

Important!

ZBrush will disable Perspective Mode if previously enabled.
From this pull direction, the coin mold separation line will exist at the center of the top and bottom halves

2020_06
Step 1 & 2 examples

3. Viewing in Draw Draft Analysis mode, make corrections to any red areas on the surfaces before final output.

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Step 3 example

Important!

Use sculpting brushes such as the Move brush to pull these surfaces down to an angle more suitable for removing from a mold.
Disable Draw Draft Analysis to view the mesh surface to apply a mask to areas for modifica­tion. Invert the mask, and re-enable Draw Draft Analysis to view draft angle changes
Invert the mask, and re-enable Draw Draft Analysis to view angle changes being made in real-time.

4. Clear the mask and DynaMesh to weld all surfaces together.

2020_08
Step 4 example