1. Biomorphic Form I (from imagination)
by Brian Curtis
© 2002, The McGraw-Hill Companies

2. A PowerPoint lecture series to accompany DRAWING FROM OBSERVATION

3. Schema, Schemata schema n.
1. A diagrammatic representation; an outline or a model.
2. A pattern imposed on complex reality or experience to assist in explaining it, to mediate perception, or to guide response.

4. A cylinder (with evenly spaced cross-contours originating from its central axis) and a sphere (with latitude-like lines connecting the poles) are examples of basic geometric volumes that can provide clarifying conceptual structure for irregular biomorphic forms. Basic geometric volumes can function as armatures that provide base-line organization for irregular variations in surface and form.

5. In order to create an imaginary armature that clearly and specifically corresponds to the underlying volumetric character of a biomorphic object, it is sometimes necessary to visualize composite structures that combine the characteristics of two or more basic geometric volumes.

6. Invented schema need to be clear, familiar, and predictable elementary geometric forms to function effectively as guides for cross-contour.

7. They also need to be flexible enough to approximate the unique character of complicated volumes and surfaces. You must constantly strive for a delicate balance between predictable structure and a fluctuating surface.

8. When you are combining one or more of the basic geometric solids to create an armature for an imaginary biomorphic form, draw through the simplified armature as though each element was transparent and vary the line quality to make it look like it’s moving away from the picture plane. This helps you experience the volume of the form and understand its surface.

9. Applying simplified imaginary geometric schema to irregular objects is a drawing technique that finds considerable reinforcement in perceptual psychology. Studies there have indicated that projecting simplified organization onto complicated and irregular patterns is a fundamental mechanism that is at the very heart of our perceptual processes; they point to an inherent need to compare and contrast immediate perceptions to pre-existing ideas.

10. Make sure to include cross-contour lines to the basic geometric forms that you are using before you begin adding abnormalities and irregularities. Cross-contours that make the transitions from one basic geometric form to another are particularly helpful.

11. It is an especially good idea to keep the idea of cross-contour transitions in mind when you begin inventing new surface variations so that every form you add or surface you adjust integrates with the overall structure of the form and contributes to the readability of the object you are creating.

12. The more you apply cross-contours to the surface of simplified schema, the easier it will be for you to calculate how they change direction on irregularized surfaces. The most common error in cross-contour is to apply the cross-contour to only a small portion of the surface of the form without regard for the form’s overall structural integrity.

13. The very notion of irregularity is a comparative one that depends entirely on an implied comparison to a pre-conceived understanding of regularity. When we apply a comparative conceptual schema to the perception of biomorphic forms, our sensitivity for discriminating nuances of surface and volume is substantially increased.

14. 3-D DANGER ZONES
Don’t place important dimensional information at or near eye level.
Avoid placing important spatial transitions on the apparent edges (profile) of the form.
To maximize the clarity and consistency of the illusion in your imaginary drawing, you also need to develop sensitivity to the way that the viewing angle affects the readability of the illusion of three-dimensional space. When it comes to conveying a spatial illusion, not all viewing angles are equal. Some viewpoints enhance the three-dimensional qualities of a given form, others detract from it. For example, avoid placing important dimensional information or volumetric transitions at eye level, parallel to the picture plane, on a vertical axis directly in front of you, or on the apparent edge of the form. Such placements contribute little in the way of volume and can compromise the drawing’s ability to convincingly suggest dimensionality.
Your choice of eye level affects every spatial relationship you will be creating. A consistent eye-level greatly increases the likelihood that the simplified schema will appear as a unified and integrated form in space. As the core is developing, apply a delicate grid of cross contours over and around the basic geometric forms. As you will quickly notice, where you choose to position your eye level has a direct impact on the movement of each and every cross-contour. Be generous with the application of cross-contours as you define the volume of your geometric core. The greater your familiarity with the three-dimensional surface of the simplified schema, the easier it will be for you to determine how irregularities of surface can be depicted.

15. Cross-contours should be developed gradually and in coordination with the underlying schema. Start with generalized cross-contours on the simplified geometric forms before moving on to any idiosyncratic details of form or surface. Once the core is established, cross-contours should be used to reinforce transitions between elements of compound geometric forms. Cross-contour is most effective when it is “drawn through the form.” It is helpful to think of the forms as though they are being cut cleanly in half on either the vertical or horizontal axis. This means approaching each object as though it is transparent, with each cross-contour and cross-section moving back beyond the contour edge to the back side, and then coming back out to the front around the other side.

16. Each and every cross-contour on a biomorphic form must appear consistent with the volume of the whole. The most common error in this type of drawing is to concentrate the cross-contour on the surface of the irregularity without any consideration of how those lines relate to the overall form. Because you have extensive sensory experience in dealing with objects in space, you have a natural ability to intuitively imagine how a line running across the surface of a form should appear. Rely on your tactile memory to “feel” the movement of a particular cross-contour and trace its path around, across, or down the surface. If you have difficulty in figuring out how a cross-contour changes its direction in any particular situation, try holding your hand in front of your eye as though on the surface of the observed object and “feel” your finger move across the surface . If you carefully watch the vertical and/or horizontal movement of your finger and then reproduce that same movement in your drawing, you will be able to decipher the surface characteristics of even the most complicated of irregular forms.

17. Cross-contours that only depict a localized change in surface won’t produce the sense of integrated wholeness that is the key to a superior volumetric drawing. Constantly draw through the form and refer back to the simplified geometric core as you apply the new cross-contours to surface irregularities. Each and every irregularity must integrate with the overall form. Make the surface undulate, bulge, ripple, droop, dip, and sag. Add bumps, lumps, craters, and crevices. Open-ended experimentation encourages discovery. Take chances and strive for as much surface irregularity as you can, but constantly keep in mind the importance of maintaining the underlying structural character that allows the character of the form to be clear and easily readable.

18. When constructing a three-dimensional creature from imagination, it is important to have a clear and consistent sense of the underlying geometric schema (in this case, sort of a cylinder that tapers at each end and is flattened at the bottom).

19. Complicated forms are easier to integrate if you “draw through” each of the constituent parts with gestural cross-contours that go completely around each element. By approaching the objects as though they are transparent, you are more likely to grasp how the cross-contour lines change direction as they move across the surface.

20. Emphasizing transitions is an excellent technique for a unified wholeness and for describing structural anomalies and surface irregularities. Complicated forms are easier to integrate if you “draw through” each of the constituent parts with gestural cross-contours that go completely around each element. By approaching the objects as though they are transparent you are more likely to grasp how the cross-contour lines change direction as they move across the surface.

21. Keep in mind that regardless of how clever and engaging your initial ideas might be for the forms you are creating, clever ideas do not necessarily translate to the drawing surface as readable three-dimensional forms. Personalized content is encouraged, but you must always be on your guard to avoid combining forms in ways that compromise the drawing’s ability to convey a clear, consistent and convincing illusion of form in space.

22. The final image will only be as good as it is spatially clear, consistent, and readable. Start with clear geometric schema built upon a consistent imagined eye-level relationship, and place the important surface variation where there is greatest potential for change in direction of the cross-contour lines as they move across the surface (left image). The three-quarter portrait was popularized in Renaissance Italy. It points toward this historical period’s dominant interest in the depiction of a clear and rational space. Although the illustrations above are more likely to have been inspired by exposure to twentieth-century comics than to masterpieces from the history of art, the clarity of the forms and the expressive exaggeration of its anatomy parallel the tradition that was effectively incorporated by Michelangelo into the figures on the Sistine ceiling.

23. One method that helps generate ideas on how to go about constructing an imaginary irregular three-dimensional form is to roughly base the composite structural schema on the forms of a familiar everyday object. This particular illustration of a fanciful race car was modeled after a bedroom slipper. Cross-contours promote structural integrity and are most effective when they are applied as though they were cutting through the forms at angles that are at 90° to the vertical and horizontal axes of the basic schema.

24. In order to correctly place and curve the features of this mistreated pumpkin it was first necessary to clearly delineate the spherical cross sections. It is essential to develop a thorough understanding of the underlying geometric schema before adding irregularity to the surface of the form.

25. In each of these illustrations the horizontal spherical cross-sections not only guarantee accurate placement and curvature of the features, but also serve as a way to establish consistent curvature for each of the bulging segments on the pumpkin’s surface.

26. When attempting to communicate the volumetric irregularities of biomorphic form it is ordinarily recommended that the object not be depicted with a majority of the important volumetric features facing directly toward the observer. In this case, however, the steep upward viewing angle allows for a strong illusion of the pumpkin’s volume.

27. When this lesson is introduced during the fall term of an academic year, it coincides with the ancient Celtic festival of the New Year (Samhain). The Celts believed that their yearly cycle began on the evening of the 31st of October and that the fabric of time was porous on this night. This allowed the spirits of the underworld to cross into the world of the living. To safeguard themselves from the mischievousness of the unworldly spirits, the Celts would leave treats and sweets around their dwellings to placate the visiting phantasms. When the Celts were Christianized, a number of their ancient traditions survived. Foremost among these are the Catholic Church’s designation of November 1 as All Saints Day and its unofficial social ritual (Halloween) on the previous evening. Re-enacting the mythos of the ancient Celts, children, pretending to be threatening spirits, demand treats. The techniques that you now have at your disposal are ideally suited to giving corporeal form to any mischievous spirits that you may harbor in your imagination.

28. This concludes the lecture
Biomorphic Form I
(from imagination)