Options and Presets

Viso’s visual appearance is controlled by the VisoOptions struct, which can be loaded from and saved to TOML files. This enables presets for different visualization styles.

Options Structure

#![allow(unused)]
fn main() {
pub struct VisoOptions {
    pub display: DisplayOptions,
    pub lighting: LightingOptions,
    pub post_processing: PostProcessingOptions,
    pub camera: CameraOptions,
    pub colors: ColorOptions,
    pub geometry: GeometryOptions,
    pub keybindings: KeybindingOptions,
}
}

All fields use #[serde(default)], so TOML files can be partial – only the fields you want to override need to be specified.

Display Options

#![allow(unused)]
fn main() {
pub struct DisplayOptions {
    pub show_waters: bool,           // default: false
    pub show_ions: bool,             // default: true
    pub show_solvent: bool,          // default: false
    pub lipid_mode: LipidMode,       // default: Coarse
    pub show_sidechains: bool,       // default: true
    pub show_hydrogens: bool,        // default: false
    pub backbone_color_mode: BackboneColorMode,   // default: Chain
    pub sidechain_color_mode: SidechainColorMode, // default: Hydrophobicity
    pub na_color_mode: NaColorMode,  // default: Uniform
}
}

Lighting Options

#![allow(unused)]
fn main() {
pub struct LightingOptions {
    pub light1_dir: [f32; 3],       // Primary directional light
    pub light2_dir: [f32; 3],       // Fill directional light
    pub light1_intensity: f32,      // default: 2.0
    pub light2_intensity: f32,      // default: 1.1
    pub ambient: f32,               // default: 0.45
    pub specular_intensity: f32,    // default: 0.35
    pub shininess: f32,             // default: 38.0
    pub rim_power: f32,             // default: 5.0
    pub rim_intensity: f32,         // default: 0.3
    pub rim_directionality: f32,    // default: 0.3
    pub rim_color: [f32; 3],
    pub rim_dir: [f32; 3],
    pub ibl_strength: f32,          // default: 0.6
    pub roughness: f32,             // default: 0.35
    pub metalness: f32,             // default: 0.15
}
}

Post-Processing Options

#![allow(unused)]
fn main() {
pub struct PostProcessingOptions {
    pub outline_thickness: f32,         // default: 1.0
    pub outline_strength: f32,          // default: 0.7
    pub ao_strength: f32,               // default: 0.85
    pub ao_radius: f32,                 // default: 0.5
    pub ao_bias: f32,                   // default: 0.025
    pub ao_power: f32,                  // default: 2.0
    pub fog_start: f32,                 // default: 100.0
    pub fog_density: f32,               // default: 0.005
    pub exposure: f32,                  // default: 1.0
    pub normal_outline_strength: f32,   // default: 0.5
    pub bloom_intensity: f32,           // default: 0.0
    pub bloom_threshold: f32,           // default: 1.0
}
}

Camera Options

#![allow(unused)]
fn main() {
pub struct CameraOptions {
    pub fovy: f32,          // Field of view in degrees, default: 45.0
    pub znear: f32,         // Near clip plane, default: 5.0
    pub zfar: f32,          // Far clip plane, default: 2000.0
    pub rotate_speed: f32,  // Mouse rotation sensitivity, default: 0.5
    pub pan_speed: f32,     // Mouse pan sensitivity, default: 0.5
    pub zoom_speed: f32,    // Scroll zoom sensitivity, default: 0.1
}
}

Color Options

#![allow(unused)]
fn main() {
pub struct ColorOptions {
    pub lipid_carbon_tint: [f32; 3],       // Warm beige/tan for lipid carbons
    pub hydrophobic_sidechain: [f32; 3],   // Blue for hydrophobic sidechains
    pub hydrophilic_sidechain: [f32; 3],   // Orange for hydrophilic sidechains
    pub nucleic_acid: [f32; 3],            // Light blue-violet for DNA/RNA
    pub band_default: [f32; 3],            // Purple
    pub band_backbone: [f32; 3],           // Yellow-orange
    pub band_disulfide: [f32; 3],          // Yellow-green
    pub band_hbond: [f32; 3],              // Cyan
    pub solvent_color: [f32; 3],
    pub cofactor_tints: HashMap<String, [f32; 3]>,
}
}

Geometry Options

#![allow(unused)]
fn main() {
pub struct GeometryOptions {
    pub tube_radius: f32,           // default: 0.3
    pub tube_radial_segments: u32,  // default: 8
    pub solvent_radius: f32,        // default: 0.15
    pub ligand_sphere_radius: f32,  // default: 0.3
    pub ligand_bond_radius: f32,    // default: 0.12
}
}

Keybinding Options

#![allow(unused)]
fn main() {
pub struct KeybindingOptions {
    pub bindings: HashMap<String, String>,  // action name -> key string
}
}

Default keybindings:

Loading and Saving

#![allow(unused)]
fn main() {
// Load from TOML file (partial files supported)
let options = VisoOptions::load(Path::new("presets/dark.toml"))?;

// Save to TOML file
options.save(Path::new("presets/my_preset.toml"))?;

// List available presets in a directory
let presets = VisoOptions::list_presets(Path::new("presets/"));
// Returns: ["dark", "publication", "presentation", ...]
}

Example TOML Preset

[display]
show_sidechains = true
backbone_color_mode = "Chain"

[lighting]
light1_intensity = 2.5
ambient = 0.5
specular_intensity = 0.4
shininess = 50.0

[post_processing]
outline_thickness = 1.5
outline_strength = 0.8
ao_strength = 1.0
bloom_intensity = 0.15
bloom_threshold = 0.8

[camera]
fovy = 35.0
rotate_speed = 0.4

[colors]
hydrophobic_sidechain = [0.2, 0.4, 0.85]
hydrophilic_sidechain = [0.9, 0.55, 0.15]

Applying Options at Runtime

Options are applied to the engine through dedicated methods. Display and color options trigger a scene re-sync (since the background processor needs them for mesh generation). Lighting and post-processing options are pushed directly to GPU uniforms.

#![allow(unused)]
fn main() {
// Apply post-processing options
engine.post_process.apply_options(&options, &queue);

// Apply lighting options
engine.update_lighting(&options.lighting);

// Display/color changes require a scene sync
engine.sync_scene_to_renderers(None);
}

Changes to display options (like backbone_color_mode or show_sidechains) invalidate the per-group mesh cache in the background processor, causing a full mesh regeneration on the next sync.