The unique visual characteristics of wood can evoke and regulate affect. This study quantitatively investigates the affective responses to the visual characteristics of wood radial sections based on the dimensions of valence and arousal. First, the visual characteristics of radial sections were quantified, proposing the wood color characteristic parameter (c) and density characteristic parameter (d), and defining their respective ranges. Subsequently, by controlling these visual characteristics, the study explored their influence patterns on affective valence and arousal, thereby constructing an affective response model. Finally, the model was evaluated through an eye-tracking experiment, and prediction results were correlated with eye-tracking metrics. Results indicate that the visual characteristic parameters of radial sections range within 20 < c < 80 (dark brown to light yellow) and 5 < d < 25 (dense to sparse). Lighter wood color (higher c values) and denser grain (lower d values) evoked higher valence and lower arousal, indicating emotions tending toward pleasant relaxation. The proposed model effectively predicted the correlation between sections and affects, achieving a Mean Absolute Error (MAE) of 0.2. Predicted valence and arousal values showed high correlation with pupil data, further validating the model's reliability from a physiological perspective.