Wobble Material (PBR + GLSL)

The Problem

Create an organic animated wobble effect that deforms vertices in a vertex shader while keeping full MeshPhysicalMaterial lighting, reflections, and shadows working correctly (including shadow maps), and support both procedural geometry and imported GLTF models.

Solution

• Injected custom vertex + fragment shader logic into `MeshPhysicalMaterial` using Custom Shader Material instead of replacing the whole material.
• Animated vertex displacement with 4D simplex noise, using time as the 4th dimension for smooth organic movement.
• Moved vertices along their surface normal direction for proper “inflation/deflation” wobble instead of only shifting on Y.
• Recomputed normals in the vertex shader using tangent + bitangent neighbor sampling to keep lighting correct after deformation.
• Fixed shadow artifacts by creating a matching wobble-enabled custom depth material so the shadow map deforms consistently with the mesh.
• Supported both a procedural icosahedron wobble and imported GLTF model wobble using the same shader pipeline.
• Lit the scene with an HDR environment map + directional lighting for strong PBR highlights and readable material response.
• Exposed wobble strength/frequency/time controls and color blending with live GUI tweaks for iteration.

Results

• A clean PBR wobble effect that preserves reflections, shading, and shadows while animating geometry entirely on the GPU.
• Reusable wobble shader setup that works on both primitive geometry and imported GLTF models with Draco compression.

Next

• Add optional audio-reactive wobble driven by FFT frequency bands.
• Add postprocessing bloom toggle for a more stylized look while keeping a performance-safe default.
• Support per-object wobble profiles so multiple models can animate differently in the same scene.