import { NormalBlendMode } from "./BlendModeConfig";
type Node = any;
/**
 * Handles normal map blending with various techniques
 * Each method preserves surface detail differently
 */
export declare class NormalBlender {
    /**
     * Blend two normal maps using specified technique
     * @param normal1 - Base normal (should be in tangent space [-1,1])
     * @param normal2 - Top normal (should be in tangent space [-1,1])
     * @param blendFactor - Blend amount (0-1)
     * @param mode - Blending technique to use
     */
    blend(normal1: Node, normal2: Node, blendFactor: Node, mode?: NormalBlendMode): Node;
    /**
     * Simple linear interpolation
     * Fast but can lose detail and doesn't preserve surface curvature well
     */
    private linearBlend;
    /**
     * Reoriented Normal Blending (RNB)
     * Best quality - preserves detail and curvature
     * Based on: "Blending in Detail" by Colin Barré-Brisebois
     */
    private reorientedBlend;
    /**
     * Whiteout Blending
     * Fast approximation, good for subtle details
     * Formula: n1 + n2 - (0,0,1)
     */
    private whiteoutBlend;
    /**
     * Unity Detail Normal (UDN) Blending
     * Good balance between quality and performance
     */
    private udnBlend;
    /**
     * Partial Derivative Blending
     * Preserves microsurface detail by considering normal derivatives
     * More expensive but highest quality for detailed surfaces
     */
    private partialDerivativeBlend;
    /**
     * Overlay Blending
     * Similar to color overlay but for normals
     */
    private overlayBlend;
    private overlayComponents;
    /**
     * Unpack normal from [0,1] texture space to [-1,1] tangent space
     */
    unpackNormal(normalSample: Node): Node;
    /**
     * Pack normal from [-1,1] tangent space to [0,1] texture space
     */
    packNormal(normal: Node): Node;
}
export {};
//# sourceMappingURL=NormalBlender.d.ts.map