by dpJudas » Fri Aug 31, 2018 1:06 pm
Thanks for the updated pk3. I looked into error you were experiencing with the floor/ceiling - turns out the math in the parallax shader is wrong. Here's an updated fixed version:
Code: Select all
mat3 GetTBN();
vec3 GetBumpedNormal(mat3 tbn, vec2 texcoord);
vec2 ParallaxMap(mat3 tbn);
Material ProcessMaterial()
{
mat3 tbn = GetTBN();
vec2 texCoord = ParallaxMap(tbn);
Material material;
material.Base = getTexel(texCoord);
material.Normal = GetBumpedNormal(tbn, texCoord);
material.Specular = texture(speculartexture, texCoord).rgb;
material.Glossiness = uSpecularMaterial.x;
material.SpecularLevel = uSpecularMaterial.y;
#if defined(BRIGHTMAP)
material.Bright = texture(brighttexture, texCoord);
#endif
return material;
}
// Tangent/bitangent/normal space to world space transform matrix
mat3 GetTBN()
{
vec3 n = normalize(vWorldNormal.xyz);
vec3 p = pixelpos.xyz;
vec2 uv = vTexCoord.st;
// get edge vectors of the pixel triangle
vec3 dp1 = dFdx(p);
vec3 dp2 = dFdy(p);
vec2 duv1 = dFdx(uv);
vec2 duv2 = dFdy(uv);
// solve the linear system
vec3 dp2perp = cross(n, dp2); // cross(dp2, n);
vec3 dp1perp = cross(dp1, n); // cross(n, dp1);
vec3 t = dp2perp * duv1.x + dp1perp * duv2.x;
vec3 b = dp2perp * duv1.y + dp1perp * duv2.y;
// construct a scale-invariant frame
float invmax = inversesqrt(max(dot(t,t), dot(b,b)));
return mat3(t * invmax, b * invmax, n);
}
vec3 GetBumpedNormal(mat3 tbn, vec2 texcoord)
{
#if defined(NORMALMAP)
vec3 map = texture(normaltexture, texcoord).xyz;
map = map * 255./127. - 128./127.; // Math so "odd" because 0.5 cannot be precisely described in an unsigned format
map.y = -map.y;
return normalize(tbn * map);
#else
return normalize(vWorldNormal.xyz);
#endif
}
vec2 ParallaxMap(mat3 tbn)
{
const float parallaxScale = 0.045;
const float minLayers = 8.0;
const float maxLayers = 16.0;
// Calculate fragment view direction in tangent space
mat3 invTBN = transpose(tbn);
vec3 V = normalize(invTBN * (uCameraPos.xyz - pixelpos.xyz));
vec2 T = vTexCoord.st;
float numLayers = mix(maxLayers, minLayers, clamp(abs(V.z), 0.0, 1.0)); // clamp is required due to precision loss
// calculate the size of each layer
const float layerDepth = 1.0 / numLayers;
// depth of current layer
float currentLayerDepth = 0.0;
// the amount to shift the texture coordinates per layer (from vector P)
vec2 P = V.xy * parallaxScale;
vec2 deltaTexCoords = P / numLayers;
vec2 currentTexCoords = T;
float currentDepthMapValue = texture(tex_heightmap, currentTexCoords).r;
while (currentLayerDepth < currentDepthMapValue)
{
// shift texture coordinates along direction of P
currentTexCoords -= deltaTexCoords;
// get depthmap value at current texture coordinates
currentDepthMapValue = texture(tex_heightmap, currentTexCoords).r;
// get depth of next layer
currentLayerDepth += layerDepth;
}
// get texture coordinates before collision (reverse operations)
vec2 prevTexCoords = currentTexCoords + deltaTexCoords;
// get depth after and before collision for linear interpolation
float afterDepth = currentDepthMapValue - currentLayerDepth;
float beforeDepth = texture(tex_heightmap, prevTexCoords).r - currentLayerDepth + layerDepth;
// interpolation of texture coordinates
float weight = afterDepth / (afterDepth - beforeDepth);
vec2 finalTexCoords = prevTexCoords * weight + currentTexCoords * (1.0 - weight);
return finalTexCoords;
}
Thanks for the updated pk3. I looked into error you were experiencing with the floor/ceiling - turns out the math in the parallax shader is wrong. Here's an updated fixed version:
[code]
mat3 GetTBN();
vec3 GetBumpedNormal(mat3 tbn, vec2 texcoord);
vec2 ParallaxMap(mat3 tbn);
Material ProcessMaterial()
{
mat3 tbn = GetTBN();
vec2 texCoord = ParallaxMap(tbn);
Material material;
material.Base = getTexel(texCoord);
material.Normal = GetBumpedNormal(tbn, texCoord);
material.Specular = texture(speculartexture, texCoord).rgb;
material.Glossiness = uSpecularMaterial.x;
material.SpecularLevel = uSpecularMaterial.y;
#if defined(BRIGHTMAP)
material.Bright = texture(brighttexture, texCoord);
#endif
return material;
}
// Tangent/bitangent/normal space to world space transform matrix
mat3 GetTBN()
{
vec3 n = normalize(vWorldNormal.xyz);
vec3 p = pixelpos.xyz;
vec2 uv = vTexCoord.st;
// get edge vectors of the pixel triangle
vec3 dp1 = dFdx(p);
vec3 dp2 = dFdy(p);
vec2 duv1 = dFdx(uv);
vec2 duv2 = dFdy(uv);
// solve the linear system
vec3 dp2perp = cross(n, dp2); // cross(dp2, n);
vec3 dp1perp = cross(dp1, n); // cross(n, dp1);
vec3 t = dp2perp * duv1.x + dp1perp * duv2.x;
vec3 b = dp2perp * duv1.y + dp1perp * duv2.y;
// construct a scale-invariant frame
float invmax = inversesqrt(max(dot(t,t), dot(b,b)));
return mat3(t * invmax, b * invmax, n);
}
vec3 GetBumpedNormal(mat3 tbn, vec2 texcoord)
{
#if defined(NORMALMAP)
vec3 map = texture(normaltexture, texcoord).xyz;
map = map * 255./127. - 128./127.; // Math so "odd" because 0.5 cannot be precisely described in an unsigned format
map.y = -map.y;
return normalize(tbn * map);
#else
return normalize(vWorldNormal.xyz);
#endif
}
vec2 ParallaxMap(mat3 tbn)
{
const float parallaxScale = 0.045;
const float minLayers = 8.0;
const float maxLayers = 16.0;
// Calculate fragment view direction in tangent space
mat3 invTBN = transpose(tbn);
vec3 V = normalize(invTBN * (uCameraPos.xyz - pixelpos.xyz));
vec2 T = vTexCoord.st;
float numLayers = mix(maxLayers, minLayers, clamp(abs(V.z), 0.0, 1.0)); // clamp is required due to precision loss
// calculate the size of each layer
const float layerDepth = 1.0 / numLayers;
// depth of current layer
float currentLayerDepth = 0.0;
// the amount to shift the texture coordinates per layer (from vector P)
vec2 P = V.xy * parallaxScale;
vec2 deltaTexCoords = P / numLayers;
vec2 currentTexCoords = T;
float currentDepthMapValue = texture(tex_heightmap, currentTexCoords).r;
while (currentLayerDepth < currentDepthMapValue)
{
// shift texture coordinates along direction of P
currentTexCoords -= deltaTexCoords;
// get depthmap value at current texture coordinates
currentDepthMapValue = texture(tex_heightmap, currentTexCoords).r;
// get depth of next layer
currentLayerDepth += layerDepth;
}
// get texture coordinates before collision (reverse operations)
vec2 prevTexCoords = currentTexCoords + deltaTexCoords;
// get depth after and before collision for linear interpolation
float afterDepth = currentDepthMapValue - currentLayerDepth;
float beforeDepth = texture(tex_heightmap, prevTexCoords).r - currentLayerDepth + layerDepth;
// interpolation of texture coordinates
float weight = afterDepth / (afterDepth - beforeDepth);
vec2 finalTexCoords = prevTexCoords * weight + currentTexCoords * (1.0 - weight);
return finalTexCoords;
}
[/code]