Tribes2/t2-mapper
1
0
Fork 0
mirror of https://github.com/exogen/t2-mapper.git synced 2026-01-19 20:25:01 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

make env map work on water surface

Browse source
This commit is contained in:
Brian Beck 2025-12-05 15:58:05 -08:00
parent 996c289032
commit 3ad5da1684
1 changed files with 18 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

38
src/waterMaterial.ts
View file

@ -5,7 +5,8 @@ import { ShaderMaterial, Texture, DoubleSide, Color } from "three";
*
* Based on analysis of the Torque V12 engine fluid rendering code.
* The original engine renders water in multiple passes:
* - Phase 1a/1b: Two cross-faded base texture passes, each rotated 30°
* - Phase 1a: Base texture rotated 30°
* - Phase 1b: Base texture rotated 60° with drift animation
* - Phase 3: Environment/specular map with reflection UVs
* - Fog: Integrated with Three.js scene fog (original used custom fog overlay)
*
@ -23,7 +24,6 @@ const vertexShader = /* glsl */ `
uniform float uTime;
uniform float uWaveMagnitude;
varying vec2 vUv;
varying vec3 vWorldPosition;
varying vec3 vViewVector;
varying float vDistance;
@ -38,8 +38,6 @@ const vertexShader = /* glsl */ `
}
void main() {
vUv = uv;
// Get world position for wave calculation
vec4 worldPos = modelMatrix * vec4(position, 1.0);
vWorldPosition = worldPos.xyz;
@ -68,7 +66,6 @@ const fragmentShader = /* glsl */ `
uniform sampler2D uBaseTexture;
uniform sampler2D uEnvMapTexture;
varying vec2 vUv;
varying vec3 vWorldPosition;
varying vec3 vViewVector;
varying float vDistance;
@ -146,22 +143,22 @@ const fragmentShader = /* glsl */ `
vec3 baseColor = (texColor1a.rgb * alpha1a * (1.0 - alpha1b) + texColor1b.rgb * alpha1b) / max(combinedAlpha, 0.001);
// === Phase 3: Environment map / specular ===
vec3 viewDir = normalize(vViewVector);
// Reflection UV calculation from engine
// The reflection vector is eye-to-point with positive Z
vec3 reflectVec = viewDir;
reflectVec.z = abs(reflectVec.z);
if (reflectVec.z < 0.001) reflectVec.z = 0.001;
// Reflection UV calculation from engine (fluidQuadTree.cc lines 910-962)
// Engine uses eye-to-point vector (point - eye), unnormalized.
// vViewVector is camera - worldPos (point-to-eye), so we negate it.
// Torque Z-up maps XY to UV; Three.js Y-up maps XZ to UV.
vec3 reflectVec = -vViewVector;
reflectVec.y = abs(reflectVec.y); // Y is vertical in Three.js (was Z in Torque)
if (reflectVec.y < 0.001) reflectVec.y = 0.001;
vec2 envUV;
if (vDistance < 0.001) {
envUV = vec2(0.0);
} else {
// Standard UV reflection mapping with adjustment
float value = (vDistance - reflectVec.z) / (vDistance * vDistance);
// Standard UV reflection mapping with adjustment to reduce edge emphasis
float value = (vDistance - reflectVec.y) / (vDistance * vDistance);
envUV.x = reflectVec.x * value;
envUV.y = reflectVec.y * value;
envUV.y = reflectVec.z * value; // Z maps to V in Three.js Y-up
}
// Convert from [-1,1] to [0,1]
@ -174,8 +171,9 @@ const fragmentShader = /* glsl */ `
vec4 envColor = texture2D(uEnvMapTexture, envUV);
// Blend environment map additively (GL_SRC_ALPHA, GL_ONE in original engine)
// This adds specular highlights without changing base transparency
vec3 finalColor = baseColor + envColor.rgb * uEnvMapIntensity;
// Engine uses GL_MODULATE with color (1,1,1,envMapIntensity), so texture alpha
// is multiplied with intensity before additive blend.
vec3 finalColor = baseColor + envColor.rgb * envColor.a * uEnvMapIntensity;
gl_FragColor = vec4(finalColor, combinedAlpha);
@ -208,9 +206,9 @@ export function createWaterMaterial(options?: {
fragmentShader,
transparent: true,
side: DoubleSide,
// Water writes depth so that objects behind it (like force fields) are
// properly occluded. Force fields use depthWrite: false and render after
// water, so they correctly appear in front of or behind water per-pixel.
// NOTE: Engine uses glDepthMask(GL_FALSE) for water, but we use depthWrite: true
// so that force fields (which render after water with depthWrite: false) are
// correctly occluded per-pixel when underwater.
depthWrite: true,
fog: true,
});