Question

所以我一直试图实现凹凸贴图一段时间，我让它以某种方式工作。所以它渲染纹理和阴影是正确的，但是当光源移动时不会改变我确定它应用从光源（0,0）移动的光源而不是光源在世界中的位置。如何确定着色器中片段的世界位置？我现在有点陷入困境，任何帮助都会受到赞赏。

- 顶点着色器

    void main() 
{
    gl_TexCoord[0] = gl_MultiTexCoord0;

    // Set the position of the current vertex
    gl_Position =  gl_ProjectionMatrix * gl_ModelViewMatrix * gl_Vertex;
}

- 片段着色器

uniform sampler2D color_texture;
uniform sampler2D normal_texture;
uniform vec4 lightColor;
uniform vec3 falloff;
uniform vec3 lightPos;
uniform vec2 resolution;
uniform float ambience;
//uniform float lightDirection;

void main()
{
    // Extract the normal from the normal map
    vec3 normal = normalize(texture2D(normal_texture, gl_TexCoord[0].st).rgb * 2.0 - 1.0);

    // Determine where the light is positioned
    vec3 light_pos = normalize(lightPos);
    //vec3 light_pos = normalize(vec3(1.0, 1.0, 0.5));

    // Calculate the lighting diffuse value, the ambience is the darkness due to no light
    float diffuse = max(dot(normal, light_pos), 0.0);

    //direction
    float lightDir = length(vec3(lightPos.xy - (gl_FragCoord.xy / resolution.xy), lightPos.z));

    //calculate attenuation
    float attenuation = 1.0 / ( falloff.x + (falloff.y*lightDir) + (falloff.z*lightDir*lightDir) );

    //calculate the final color
    vec3 color = diffuse * texture2D(color_texture, gl_TexCoord[0].st).rgb;

    // Set the output color of our current pixel
    gl_FragColor = vec4(color, 1.0);
}

- jogl，java代码连接着色器

int shaderProgram = ShaderControl.enableShader(gl, shaderName);

        //apply vars
        int diffuseTextureVariableLocation = gl.getGL2().glGetUniformLocation(shaderProgram, "color_texture");
        int normalColorVariableLocation = gl.getGL2().glGetUniformLocation(shaderProgram, "normal_texture");
        int lightPositionVariableLocation = gl.getGL2().glGetUniformLocation(shaderProgram, "lightPos");
        int lightColorVariableLocation = gl.getGL2().glGetUniformLocation(shaderProgram, "lightColor");
        int falloffVariableLocation = gl.getGL2().glGetUniformLocation(shaderProgram, "falloff");
        int resolutionVariableLocation = gl.getGL2().glGetUniformLocation(shaderProgram, "resolution");
        int ambienceVariableLocation = gl.getGL2().glGetUniformLocation(shaderProgram, "ambience");

        gl.getGL2().glUniform1i(diffuseTextureVariableLocation, 0);
        gl.getGL2().glUniform1i(normalColorVariableLocation, 1);
        gl.getGL2().glUniform3f(lightPositionVariableLocation, positionLight.x, positionLight.y, 1.5f);
        gl.getGL2().glUniform4f(lightColorVariableLocation, 1f, 1.0f, 1.0f, 1f);
        gl.getGL2().glUniform3f(falloffVariableLocation,.4f, 3f, 20f);
        gl.getGL2().glUniform2f(resolutionVariableLocation, Game._viewPortDimension.width, Game._viewPortDimension.height);
        gl.getGL2().glUniform1f(ambienceVariableLocation, 0.93f);

        gl.getGL2().glActiveTexture(GL2.GL_TEXTURE1);
        normalTexture.bind(gl);

        //bind diffuse color to texture unit 0
        gl.getGL2().glActiveTexture(GL2.GL_TEXTURE0);
        texture.bind(gl);

        //draw the texture and apply the bump mapping shader
        drawTexture(gl, worldOffsetX, worldOffsetY, x, y, depth, rotation, percentageToDraw, width, height, texture);

        ShaderControl.disableShader(gl);

亲切的问候 Johandre

Answer 1

首先，确保你真的需要它。完成后，您可以在片段着色器中创建varying vec3，从包含世界位置的顶点着色器进行插值。为此，请确保您具有单独的模型视图矩阵和投影矩阵。（我更喜欢到目前为止我只制作了一个投影矩阵）。使用模型视图矩阵的输出作为varying vec3。

在glsl，JOGL中的顶点世界位置

1 个答案: