Molecular modeling can get complex, especially when you need precise control over the positioning of structures, atoms, or meshes. Whether you’re aligning molecules for analysis or distributing structures to create better models, SAMSON’s move editors provide a powerful set of tools for tackling these challenges.
In this post, we’ll dive into the practical aspects of using SAMSON’s move editors, such as the Displacer, Local Move Editor, and Global Move Editor, for translating, rotating, and aligning your molecular objects with ease.
The Types of Move Editors
SAMSON offers three types of move editors, each tailored for specific uses:
- Displacer (D): Ideal for moving objects in the plane of the camera, suitable for interactive simulations requiring quick adjustments.
- Local Move Editor (M): Provides translation and rotation along the local principal axes of the selection, enabling intricate local adjustments like editing dihedral angles.
- Global Move Editor (K): Translates and rotates objects along the global XYZ axes, perfect for structured global alignments.
These move editors can be accessed via the left-side menu in the SAMSON viewport. Before we explore their features, it’s important to note that objects must first be selected before performing any positioning actions.
How to Use the Local Move Editor
The Local Move Editor is particularly powerful for translating and rotating objects along their own axes. This editor allows you to:
- Use the central translation widget (a cross with arrows) to move objects in the plane of the camera.
- Employ side translation widgets (straight arrows and planes) to move objects precisely along principal axes of the selected objects.
- Use rotation widgets for accurate rotations around principal axes or use the trackball widget for free rotations.
All translation or rotation actions provide visual feedback, with options for cancelling adjustments (press Esc) or undoing them via Edit > Undo. Translational and rotational snapping options are available and can be customized in the viewport’s quick access menu or the Preferences settings.
Working with the Global Move Editor
When aligning objects globally, the Global Move Editor is your tool of choice. It provides:
- Translation and rotation aligned with global XYZ axes (represented by red, green, and blue widgets).
- The ability to move objects intuitively using arrows and planes attached to these global axes.
- Rotational adjustments through curved rotation widgets or via the trackball for free movement.
Both Local and Global Move Editors allow you to enhance precision with snapping functionalities, enabling translational snapping (e.g., 0.5Å) and rotational snapping (e.g., 10°). These preferences can be quickly toggled for efficient model adjustments.
Optimizing Your Workflow Using Move Editors
For tasks such as aligning molecular fragments or fine-tuning molecular geometries, SAMSON’s move editors reduce the manual effort. For example, you can edit dihedral angles by clicking on a fragment’s bond and rotating it directly. Moreover, both Local and Global Move Editors provide contextual menus for customizable translations and rotations, either interactively or by inputting precise numerical values.
By incorporating these tools into your workflow, you can efficiently align, distribute, and fine-tune molecular models—all critical steps for accurate simulations and presentations.
Conclusion
By mastering SAMSON’s move editors, molecular modelers can achieve precision in adjusting and aligning structures, making it easier to focus on their scientific investigations and insights. To dive deeper into these tools and practical examples, refer to the complete documentation at this link.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at SAMSON Connect.