Setting Default Viewport Clipping Values In Blender To Improve Workflow
Improving Viewport Performance by Setting Default Clipping Values
The viewport clipping planes in Blender determine the limits of the visible area when viewing and navigating a scene. Setting appropriate default clip start and end values can optimize viewport performance and speed up your workflow.
Having clipping planes that are too far apart results in Blender having to process and render geometry that is beyond what is visible in the viewport. This slows down manipulation, navigation, and editing. By setting closer clip distances, you can improve viewport interaction speed and responsiveness.
What are Viewport Clipping Planes and Why They Matter
The viewport clip start and end settings define front and back clipping planes perpendicular to the viewing direction. Any geometry in front of the clip start plane or beyond the clip end plane will not be visible.
Narrowing the gap between clipping planes to closely bracket the visible region allows Blender to cull and disregard occluded or distant geometry. This decreases the number of faces and vertices that require processing and speeds up viewport rendering.
Finding clipping values that clip as close to the scene as possible, without clipping away required visible elements, results in optimal viewport performance. Tighter clips also reduce artifacting such as z-fighting.
Finding the Optimal Clipping Range for Your Scene
Evaluating Scene Scale and Camera Position
Assessing the scale and camera placements in your scene is crucial for determining suitable clip start and end values. Large environments naturally require more distant clipping to avoid culling integral visible areas.
Likewise, extreme camera zooms for close-ups necessitate adjusting clips appropriately. Analyze scene content from all required viewpoints to find clipping ranges that accommodate all cameras and viewport needs.
Testing Different Clipping Values
Experiment with incremental clip start and end distances to evaluate their impact on visual quality and viewport speed. Narrow and expand clipping planes to find the closest settings before visual elements begin disappearing.
Take note of responsiveness and frame rates during viewport navigation with different clips. Tighten the clip range until performance starts to suffer or artifacts appear due to excess culling.
Setting Default Clip Start and End Values
Using Python to Set Defaults
For convenience, use Python scripting to define default clip start and end values rather than adjusting them manually each session. This ensures a consistent optimized environment.
Simply insert script calls to bpy.context.space_data.clip_start and bpy.context.space_data.clip_end in your startup scripts to configure suitable clip distances on loading Blender.
Adding Clipping Settings to Config Files
Alternatively, default clip start and end values can be specified in Blender’s configuration files for permanent effect. This avoids the need for Python scripting to set the values.
Add clipstart and clipend variables under the viewport_clip setting in your Blender user config file. These will then persist as defaults for all projects.
Maximizing Viewport Speed While Modeling
Disabling Clip Planes During Modeling
While modeling detailed assets and sculptures, clipping planes may need to be disabled temporarily for full visual access when working up close.
Toggle the viewport clip setting off while editing object geometry at the micro level. This prevents important vertices or edges from being unintentionally clipped and hidden.
Re-enabling Clips Before Rendering
Be sure to re-enable clipping planes once the base modeling work is complete though. The optimized clip ranges determined earlier should then be set before proceeding to texture, animate, or render the full scene.
Render previews will reflect final output more accurately with suitable clipping configured rather than modeling with no clips enabled.
Clipping Tips and Tricks
Using Separate Clips for Different Viewports
For complex scenes, consider defining separate custom clip start and end values per individual editor viewport. This allows optimizing the clipping range independently for each tab.
The Active Camera view can prioritize visible geometry from the current camera perspective. Other views may have different needs regarding clip distances for their content.
Animating Clipping Planes
In some cases, animating the viewport clip distances dynamically can be useful. This allows the visible clip range to adjust automatically on cue during animation playback.
By keyframing the Start and End properties under the View Clip setting, the clipping planes can match camera moves or scene changes to maintain optimal context visible.
