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Module 2 • Lesson 3🧵 Surfaces & 3D

The last integration frontier is dimension. A graphic must sink into a fabric's folds, glass must bend what's behind it, and a CGI render must arrive as separable light. Displacement maps, refraction, and multi-pass compositing turn flat overlays into things that live on real surfaces.

📚 What You'll Learn

By the end of this lesson, you will be able to:

  • Use a displacement map to wrap a graphic onto a textured surface's geometry
  • Blend the wrapped graphic so it picks up the surface's light and shadow
  • Fake glass and refraction — see-through with distortion and speculars
  • Understand a multi-pass CGI render (beauty, depth, AO, specular) and comp it
  • Tie it all to Module 1's blend math and 32-bit light

⏱️ Estimated Time: 60 minutes

🎯 Project (module deliverable): A graphic displaced convincingly onto a textured surface, plus a glass or render element integrated with it.

In This Lesson

👤 The Goal: On the Surface, Not On Top

The same logo on the same folded fabric. On the right, a flat decal — straight lines ignoring every crease, obviously pasted. On the left, a displacement map bends the logo along the folds and a blend lets the fabric's shadows fall across it, so it reads as printed into the cloth. Drag the handle:

Displaced Flat decal
A diagram of the principle. The fabric's own light and dark folds become a map that pushes the logo's pixels around, and a blend mode lets the cloth's shadows cross it — so it belongs to the surface.

🧠 Mental Model: Luminance Is Geometry

You have no 3D model of the fabric — but you don't need one, because the brightness of the surface already encodes its shape. Where cloth bulges toward the light it's bright; where it folds away it's dark. A displacement map reads that luminance and uses it to shove an overlay's pixels: bright areas push one way, dark the other, so the overlay deforms to follow geometry it can't see.

Displacement handles the shape; a blend mode handles the light. After displacing, shade it. For a dark graphic on a lighter surface, set the graphic to Multiply (or Linear Burn) so the surface's shadows darken it in the folds. Multiply can never darken white, though, so for a light graphic (like the white logo above) keep it on Normal and clip a desaturated copy of the surface above it, set to Multiply, with Levels pushing its lit areas to white so only the folds darken the art. Either way it stops being an overlay and becomes part of the material. Two steps: deform, then shade.

Luminance map pushes pixels overlay deforms the surface's own brightness is the geometry — no 3D needed
Figure 1: A displacement map is just the surface's luminance. Its light/dark values offset the overlay's pixels, bending straight lines to ride the folds.

🗺️ The Displacement Map

The workflow: prepare the map, then displace against it. Make the map: use Image ▸ Duplicate (Duplicate Merged Layers Only) to make a separate document at the same pixel size, desaturate it, blur slightly (a few px, to smooth noise into shape), and save it as its own .psd. Displace the overlay: select the graphic layer and run Filter ▸ Distort ▸ Displace, set horizontal/vertical scale (start ~10), click OK, and choose that saved .psd in the file dialog. Then shade the graphic so the folds cross it (Multiply for dark art, a clipped shading layer for light art).

Filter ▸ Distort ▸ Displace
Horizontal Scale 10 Vertical Scale 10 ✓Stretch To Fit ✓Repeat Edge Pixels Choose displacement map: surface_map.psd → then shade it into the folds
Figure 2: Displace reads a saved .psd map. Higher scale = more deformation; too much tears the graphic. Stretch To Fit/Tile and Wrap Around/Repeat Edge Pixels are two pairs of radio options. After displacing, shade the graphic so the surface's shadows fall across it.

⚠️ Blur the map, or you displace the noise

A displacement map should carry shape, not grain. If you skip the slight blur, every fabric fiber and sensor speck becomes a tiny offset and the graphic gets a jittery, chewed edge. Smooth the map to the folds you actually want to follow.

🔮 Glass, Refraction & Render Passes

Glass and refraction are the same idea aimed at transparency. A glass element shows what's behind it, distorted: copy the background behind the glass, displace it or use Filter ▸ Filter Gallery ▸ Distort ▸ Glass (the Filter Gallery needs an 8-bit document) to bend the view, and add speculars and edge highlights on Screen. Real glass is mostly its edges, highlights, and the distortion, not a gray shape.

Integrating a CGI render is where Module 1 pays off. A render doesn't arrive as one picture but as passes: a beauty pass, plus depth, ambient occlusion, specular, and shadow passes, often as 32-bit EXR. Ask for each pass as its own EXR file; Photoshop's built-in OpenEXR support does not split a multilayer EXR into separate layers (that needs a third-party plug-in). You composite them: Multiply the AO for contact shadow and Linear Dodge (Add) the specular for highlights. In 32-bit, Screen is not available, so Add is the mode for light. Working in 32-bit keeps the render's real light intact.

The depth pass drives defocus: paste it into a new alpha channel, then run Filter ▸ Blur ▸ Lens Blur (Lesson 2.2) with Depth Map Source set to that channel and click where focus should fall. Lens Blur may not be available in 32-bit on your version; if it's grayed out, do this step on a 16-bit copy after the pass comp.

Depth → drives DoF Specular — Add AO — Multiply Beauty pass A render is separable light: recombine passes with the blend math from Module 1 (Multiply, Add) in 32-bit light.
Figure 3: A CGI render as passes. You are not "pasting a 3D object" — you are recombining its light with the same Multiply and Add math you learned in Module 1, which is what lets you match it to the plate.

✅ Everything in this module compounds

A fully integrated render gets the edge work (2.1), the capture match — grain, CA, DoF from its depth pass (2.2), and pass compositing in 32-bit (this lesson, and Module 1). Photoreal integration is never one trick; it's all of them, each removing one more tell.

🛠️ Guided Build: Wrap a Graphic

Grab a photo of a textured surface with clear folds or weave (fabric, a flag, a knit sweater) and a logo or text to apply.

Step 1: Make the map · 8 min

  1. With the surface photo open, choose Image ▸ Duplicate (tick Duplicate Merged Layers Only if the option appears; it only shows when the document has more than one layer). Keep the copy at exactly the same pixel size as the surface document; don't crop it.
  2. In the copy, Image ▸ Adjustments ▸ Desaturate, then apply a small Gaussian Blur (2–4 px) to keep shape and drop noise.
  3. Save it as its own surface_map.psd and close it. Keep the file; Displace reads it from disk.

Step 2: Displace the graphic · 10 min

  1. Back in the surface document, place your graphic (File ▸ Place Embedded), position and size it, then duplicate the layer and hide the copy: that hidden Smart Object is your editable original.
  2. Rasterize the visible one (Layer ▸ Rasterize ▸ Smart Object). Displace reads the map in the coordinates of the layer it runs on; on a plain layer that is the document canvas, the same size as your map, so the bends land on the folds. Run as a Smart Filter, the map can be fitted to the graphic's own bounds instead, and the bends drift off the folds.
  3. Filter ▸ Distort ▸ Displace, scale ~10/10, Stretch To Fit, click OK, then choose surface_map.psd.
  4. Adjust scale until it follows the folds without tearing: undo and reopen the dialog with Ctrl+Alt+F / Cmd+Option+F (Filter ▸ Last Filter with its dialog), or rebuild from the hidden copy if you need to move the graphic.

Step 3: Shade it into the material · 10 min

  1. Dark graphic: set it to Multiply (or Linear Burn) so the fabric's shadows cross it; drop opacity slightly.
  2. Light graphic: keep it on Normal. Duplicate the surface layer, desaturate it, move it directly above the graphic, and clip it (Alt/⌥-click between the layers). Set it to Multiply and use Levels to push its lit areas to white, so only the folds darken the art.
  3. Optionally add a mask to fade the graphic where the cloth turns steeply away.

Step 4: Add a glass or render element · 8 min

  1. For glass: copy the background behind it, Glass/Displace to distort, add Screen speculars and edge highlights.
  2. For a render: Multiply the AO, Add (Linear Dodge) the specular, drive DoF from the depth pass.
  3. Finish the whole piece with the edge work from 2.1 and a unified grain from 2.2. Save as surfaces.psd. Module 2 deliverable complete. 🏆

✅ Project Completion Checklist (Module 2 deliverable)

  • ☐ A blurred, desaturated displacement map saved as its own .psd
  • ☐ Graphic displaced to follow the surface without tearing
  • ☐ Graphic shaded by the folds (Multiply for dark art, a clipped shading layer for light art)
  • ☐ A glass element (refraction + speculars) or a comped render pass
  • ☐ Edge + capture match from 2.1/2.2 applied to the result

🧗 Now You: Solo Variation

🌟 Your challenge

  1. Displace the same logo onto three surfaces — fabric, skin, and cracked earth — and tune the scale and blend for each material.
  2. Composite a drinking glass or bottle over a scene so the background bends through it and the rim catches a specular. Sell it with edges, not fill.
  3. If you have access to any render passes (even a free sample EXR), practice recombining beauty + AO + specular and driving DoF from depth.

Going further: make the displacement live. Create a new document at exactly the surface document's pixel size (File ▸ New), then Shift-drag the hidden Smart Object into it; between same-size documents, Shift keeps it in the same position. Save that file as artwork.psd and File ▸ Place Embedded it into the surface document: a file the same size as the canvas lands exactly aligned, so the Smart Object's bounds match the map. Now Displace can run on it as an editable Smart Filter: change the artwork inside and Photoshop re-applies the displacement (as long as the map .psd is still on disk), giving you a live mockup on a textured surface. Compare it with your rasterized version at 100% to confirm the bends land on the folds.

🍳 Recipe Card: Surfaces & 3D

Deform, shade, refract, recombine

  1. Map: Image ▸ Duplicate (same size) → desaturate → slight blur → save as .psd
  2. Displace the graphic against the map (scale to taste, don't tear)
  3. Shade it: Multiply for dark art, a clipped Multiply shading layer for light art
  4. Glass: distort the background behind it (Displace or Filter Gallery ▸ Glass) + Screen speculars/edges
  5. Render: Multiply AO, Add specular, depth → DoF, in 32-bit

Mantra: brightness is geometry — let the surface's own light bend and shade what you lay on it.

📓 Learning Journal

Add to your journal after this lesson:

  • Key concepts you learned
  • Techniques that clicked for you
  • Questions or confusion points to revisit
  • Ideas you want to try
  • Your progress and feelings about learning this

✍️ This lesson's prompt: Where have you seen a "flat decal" mockup that broke the illusion? What would a displacement map and proper shading have fixed?

📝 Module 2 Summary

🎓 Key Takeaways

  • A perfect mask makes a silhouette; edge work (defringe, light wrap, color bleed) makes a photograph.
  • Match the plate's optical signature — grain, noise, chromatic aberration, and depth of field.
  • Displacement maps use a surface's luminance as geometry to wrap graphics onto it.
  • Glass is distortion + speculars; a render is separable passes recombined with blend math in 32-bit.

🎉 What You've Accomplished — Across All of Module 2

You can now make an added element optically indistinguishable from the plate: its edge belongs, it shares the lens's signature, and it lives on real surfaces and in real dimension. This is the compositing that ads, films, and album covers are built on — and it rests directly on the color science of Module 1.

❓ Common Questions at This Stage

My displaced graphic looks warped but still "on top". Why?

You did the deform but not the shade. Displacement handles shape; you still need the surface's shadows to fall across the graphic: Multiply or Linear Burn for dark art, or a clipped Multiply shading layer for light art (Multiply can't darken white). Shape without shading is only half the illusion.

Do I need a 3D app for the render parts?

Not to composite them — Photoshop recombines render passes beautifully with blend modes and 32-bit. You need a 3D app only to create the passes. Knowing how to comp them is the skill that makes you valuable on a CGI-heavy job.

🔭 Looking Ahead

You've made things belong to a scene. Next you make people flawless: Module 3 — Beauty & Product Retouching Mastery takes retouching from natural to agency-grade, and tackles the hardest surfaces of all — chrome, glass, and liquid.

✅ Before the Next Module

  • Fully integrate one composite through 2.1 → 2.2 → 2.3.
  • Wrap a graphic onto a real textured surface with a displacement map.
  • Write your Learning Journal entry.

📚 Additional Resources

🌟 Encouragement for the Journey

Photoreal compositing is equal parts science and patience — a dozen small, honest fixes that each remove one tell. You now know all of them. The next time a composite "just looks off", you'll be able to name exactly why and fix it. On to the human face.