Mesas y luminarias LibGDX.
Estoy tratando de conseguir que las normales de malla y las luces funcionen en el proyecto LibGDX.
Ya tengo malla texturizada generada a partir de píxeles de textura de altura.
El problema Es que no puedo iluminar las normales correctamente. Tampoco estoy 100% seguro de que tengo los vértices normales configurados correctamente en la clase TerrainChunk.
Aquí está el código principal de la clase:
package com.me.terrain;
import com.badlogic.gdx.Game;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.files.FileHandle;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Mesh;
import com.badlogic.gdx.graphics.PerspectiveCamera;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.VertexAttribute;
import com.badlogic.gdx.graphics.VertexAttributes.Usage;
import com.badlogic.gdx.graphics.g3d.utils.CameraInputController;
import com.badlogic.gdx.graphics.glutils.ShaderProgram;
import com.badlogic.gdx.math.Matrix3;
import com.badlogic.gdx.math.Matrix4;
import com.badlogic.gdx.math.Vector3;
public class Terra extends Game {
private PerspectiveCamera camera;
private CameraInputController camController;
private TerrainChunk chunk;
private Mesh mesh;
private ShaderProgram shader;
private Texture terrainTexture;
private final Matrix3 normalMatrix = new Matrix3();
private static final float[] lightPosition = { 5, 35, 5 };
private static final float[] ambientColor = { 0.2f, 0.2f, 0.2f, 1.0f };
private static final float[] diffuseColor = { 0.5f, 0.5f, 0.5f, 1.0f };
private static final float[] specularColor = { 0.7f, 0.7f, 0.7f, 1.0f };
private static final float[] fogColor = { 0.2f, 0.1f, 0.6f, 1.0f };
private Matrix4 model = new Matrix4();
private Matrix4 modelView = new Matrix4();
private final String vertexShader =
"attribute vec4 a_position; \n" +
"attribute vec3 a_normal; \n" +
"attribute vec2 a_texCoord; \n" +
"attribute vec4 a_color; \n" +
"uniform mat4 u_MVPMatrix; \n" +
"uniform mat3 u_normalMatrix; \n" +
"uniform vec3 u_lightPosition; \n" +
"varying float intensity; \n" +
"varying vec2 texCoords; \n" +
"varying vec4 v_color; \n" +
"void main() { \n" +
" vec3 normal = normalize(u_normalMatrix * a_normal); \n" +
" vec3 light = normalize(u_lightPosition); \n" +
" intensity = max( dot(normal, light) , 0.0); \n" +
" v_color = a_color; \n" +
" texCoords = a_texCoord; \n" +
" gl_Position = u_MVPMatrix * a_position; \n" +
"}";
private final String fragmentShader =
"#ifdef GL_ES \n" +
"precision mediump float; \n" +
"#endif \n" +
"uniform vec4 u_ambientColor; \n" +
"uniform vec4 u_diffuseColor; \n" +
"uniform vec4 u_specularColor; \n" +
"uniform sampler2D u_texture; \n" +
"varying vec2 texCoords; \n" +
"varying vec4 v_color; \n" +
"varying float intensity; \n" +
"void main() { \n" +
" gl_FragColor = v_color * intensity * texture2D(u_texture, texCoords); \n" +
"}";
@Override
public void create() {
// Terrain texture size is 128x128
terrainTexture = new Texture(Gdx.files.internal("data/concrete2.png"));
// Height map (black/white) texture size is 32x32
String heightMapFile = "data/heightmap.png";
// position, normal, color, texture
int vertexSize = 3 + 3 + 1 + 2;
chunk = new TerrainChunk(32, 32, vertexSize, heightMapFile);
mesh = new Mesh(true, chunk.vertices.length / 3, chunk.indices.length,
new VertexAttribute(Usage.Position, 3, ShaderProgram.POSITION_ATTRIBUTE),
new VertexAttribute(Usage.Normal, 3, ShaderProgram.NORMAL_ATTRIBUTE),
new VertexAttribute(Usage.ColorPacked, 4, ShaderProgram.COLOR_ATTRIBUTE),
new VertexAttribute(Usage.TextureCoordinates, 2, ShaderProgram.TEXCOORD_ATTRIBUTE));
mesh.setVertices(chunk.vertices);
mesh.setIndices(chunk.indices);
camera = new PerspectiveCamera(67, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
camera.position.set(5, 50, 5);
camera.direction.set(3, 0, 0).sub(camera.position).nor();
camera.near = 0.005f;
camera.far = 300;
camera.update();
camController = new CameraInputController(camera);
Gdx.input.setInputProcessor(camController);
ShaderProgram.pedantic = false;
shader = new ShaderProgram(vertexShader, fragmentShader);
}
@Override
public void render() {
Gdx.gl.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
Gdx.gl.glEnable(GL20.GL_DEPTH_TEST);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);
camController.update();
camera.update();
// This is wrong?
model.setToRotation(new Vector3(0, 1, 0), 45f);
modelView.set(camera.view).mul(model);
terrainTexture.bind();
shader.begin();
shader.setUniformMatrix("u_MVPMatrix", camera.combined);
shader.setUniformMatrix("u_normalMatrix", normalMatrix.set(modelView).inv().transpose());
shader.setUniform3fv("u_lightPosition", lightPosition, 0, 3);
shader.setUniform4fv("u_ambientColor", ambientColor, 0, 4);
shader.setUniform4fv("u_diffuseColor", diffuseColor, 0, 4);
shader.setUniform4fv("u_specularColor", specularColor, 0, 4);
shader.setUniformi("u_texture", 0);
mesh.render(shader, GL20.GL_TRIANGLES);
shader.end();
}
}
Código de clase TerrainChunk:
final static class TerrainChunk {
public final float[] heightMap;
public final short width;
public final short height;
public final float[] vertices;
public final short[] indices;
public final int vertexSize;
private final int positionSize = 3;
public TerrainChunk(int width, int height, int vertexSize, String heightMapTexture) {
if ((width + 1) * (height + 1) > Short.MAX_VALUE) {
throw new IllegalArgumentException(
"Chunk size too big, (width + 1)*(height+1) must be <= 32767");
}
this.heightMap = new float[(width + 1) * (height + 1)];
this.width = (short) width;
this.height = (short) height;
this.vertices = new float[heightMap.length * vertexSize];
this.indices = new short[width * height * 6];
this.vertexSize = vertexSize;
buildHeightmap(heightMapTexture);
buildIndices();
buildVertices();
calcNormals(indices, vertices);
}
public void buildHeightmap(String pathToHeightMap) {
FileHandle handle = Gdx.files.internal(pathToHeightMap);
Pixmap heightmapImage = new Pixmap(handle);
Color color = new Color();
int idh = 0;
for (int x = 0; x < this.width + 1; x++) {
for (int y = 0; y < this.height + 1; y++) {
Color.rgba8888ToColor(color, heightmapImage.getPixel(x, y));
this.heightMap[idh++] = color.r;
}
}
}
public void buildVertices() {
int heightPitch = height + 1;
int widthPitch = width + 1;
int idx = 0;
int hIdx = 0;
int strength = 10; // multiplier for height map
float scale = 4f;
for (int z = 0; z < heightPitch; z++) {
for (int x = 0; x < widthPitch; x++) {
// POSITION
vertices[idx++] = scale * x;
vertices[idx++] = heightMap[hIdx++] * strength;
vertices[idx++] = scale * z;
// NORMAL, skip these for now
idx += 3;
// COLOR
vertices[idx++] = Color.WHITE.toFloatBits();
// TEXTURE
vertices[idx++] = (x / (float) width);
vertices[idx++] = (z / (float) height);
}
}
}
private void buildIndices() {
int idx = 0;
short pitch = (short) (width + 1);
short i1 = 0;
short i2 = 1;
short i3 = (short) (1 + pitch);
short i4 = pitch;
short row = 0;
for (int z = 0; z < height; z++) {
for (int x = 0; x < width; x++) {
indices[idx++] = i1;
indices[idx++] = i2;
indices[idx++] = i3;
indices[idx++] = i3;
indices[idx++] = i4;
indices[idx++] = i1;
i1++;
i2++;
i3++;
i4++;
}
row += pitch;
i1 = row;
i2 = (short) (row + 1);
i3 = (short) (i2 + pitch);
i4 = (short) (row + pitch);
}
}
// Gets the index of the first float of a normal for a specific vertex
private int getNormalStart(int vertIndex) {
return vertIndex * vertexSize + positionSize;
}
// Gets the index of the first float of a specific vertex
private int getPositionStart(int vertIndex) {
return vertIndex * vertexSize;
}
// Adds the provided value to the normal
private void addNormal(int vertIndex, float[] verts, float x, float y, float z) {
int i = getNormalStart(vertIndex);
verts[i] += x;
verts[i + 1] += y;
verts[i + 2] += z;
}
/*
* Normalizes normals
*/
private void normalizeNormal(int vertIndex, float[] verts) {
int i = getNormalStart(vertIndex);
float x = verts[i];
float y = verts[i + 1];
float z = verts[i + 2];
float num2 = ((x * x) + (y * y)) + (z * z);
float num = 1f / (float) Math.sqrt(num2);
x *= num;
y *= num;
z *= num;
verts[i] = x;
verts[i + 1] = y;
verts[i + 2] = z;
}
/*
* Calculates the normals
*/
private void calcNormals(short[] indices, float[] verts) {
for (int i = 0; i < indices.length; i += 3) {
int i1 = getPositionStart(indices[i]);
int i2 = getPositionStart(indices[i + 1]);
int i3 = getPositionStart(indices[i + 2]);
// p1
float x1 = verts[i1];
float y1 = verts[i1 + 1];
float z1 = verts[i1 + 2];
// p2
float x2 = verts[i2];
float y2 = verts[i2 + 1];
float z2 = verts[i2 + 2];
// p3
float x3 = verts[i3];
float y3 = verts[i3 + 1];
float z3 = verts[i3 + 2];
// u = p3 - p1
float ux = x3 - x1;
float uy = y3 - y1;
float uz = z3 - z1;
// v = p2 - p1
float vx = x2 - x1;
float vy = y2 - y1;
float vz = z2 - z1;
// n = cross(v, u)
float nx = (vy * uz) - (vz * uy);
float ny = (vz * ux) - (vx * uz);
float nz = (vx * uy) - (vy * ux);
// normalize(n)
float num2 = ((nx * nx) + (ny * ny)) + (nz * nz);
float num = 1f / (float) Math.sqrt(num2);
nx *= num;
ny *= num;
nz *= num;
addNormal(indices[i], verts, nx, ny, nz);
addNormal(indices[i + 1], verts, nx, ny, nz);
addNormal(indices[i + 2], verts, nx, ny, nz);
}
for (int i = 0; i < (verts.length / vertexSize); i++) {
normalizeNormal(i, verts);
}
}
}
Lo que veo es que cuando muevo la cámara, las luces no se muestran correctamente cuando estoy sobre el terreno. Se muestran más cuando estoy debajo del terreno, aunque de manera incorrecta incluso entonces creo.
fotos:
