将一组矢量传递给制服 [英] Passing an array of vectors to a uniform
问题描述
我正在尝试在着色器中实现多个灯光,但是我无法用我的光照数据填充制服。
I am trying to implement multiple lights in my shader but I have trouble to fill the uniform with my light data.
我的顶点着色器:
attribute vec3 aVertex;
attribute vec3 aNormal;
attribute vec2 aTexture;
uniform mat4 uMVMatrix;
uniform mat4 uPMatrix;
uniform mat4 uNMatrix;
uniform vec3 uAmbientColor;
uniform vec3 uPointLightingLocation[16];
uniform vec3 uPointLightingColor[16];
varying vec2 vTexture;
varying vec3 vLightWeighting;
void main(void) {
vec4 mvPosition = uMVMatrix * vec4(aVertex, 1.0);
gl_Position = uPMatrix * mvPosition;
vTexture = aTexture;
int i;
for (i = 0; i < 16; i++) {
vec3 lightDirection = normalize(uPointLightingLocation[i] - mvPosition.xyz);
vec4 transformedNormal = uNMatrix * vec4(aNormal, 1.0);
float directionalLightWeighting = max(dot(transformedNormal.xyz, lightDirection), 0.0);
if (i == 0) {
vLightWeighting = uAmbientColor + uPointLightingColor[i] * directionalLightWeighting;
} else {
vLightWeighting = vLightWeighting * (uAmbientColor + uPointLightingColor[i] * directionalLightWeighting);
}
}
}
仅显示最新信息的代码光:
Code that shows only the latest light:
for (var light in this.lightsDirection) {
gl.uniform3fv(this.shaderProgram.pointLightingLocationUniform, this.lightsDirection[light]);
gl.uniform3fv(this.shaderProgram.pointLightingColorUniform, this.lightsColor[light]);
}
作为制服 uPointLightingLocation
是一个大小为16的vec3数组,我认为可以将整个数组传递给制服,但我没有工作解决方案。
As the uniform uPointLightingLocation
is a vec3 array with the size of 16, I thought that it would be possible to pass the complete array to the uniform, but I have no working solution.
我尝试传递完整的数组 this.lightsColor
(没有索引)我看不到任何光。
When I try to pass the complete array this.lightsColor
(without the index) I see no light at all.
推荐答案
gl.uniform3fv需要一个扁平的浮点数组。此外,您使用相同的统一位置多次调用它。所以,最后一个获胜。想象一下,uniform3fv是一个低级复制命令,你给它(目标,源)。它只是将一个缓冲区从一个地方复制到另一个地方。
gl.uniform3fv expects a flattened array of floats. Also, you are calling it multiple times with the same uniform location. So, the last one wins. Imagine that uniform3fv is a low-level copy command, and you give it (destination, source). It just copies a buffer from one place to another.
假设你的例子只有3个灯,你可以这样统一分配位置:
Assuming your example has only 3 lights, you could assign the location uniform this way:
var locations = [
1.0, 0, 0,
0, 1.0, 0,
0, 0, 0
];
gl.uniform3fv(shaderProgram.pointLightingLocationUniform, locations);
我还建议您在调试此类问题时使用更简单的着色器。在顶点着色器中使用以下内容:
I would also recommend using a more simple shader when you are debugging problems like this. With something like the following in your vertex shader:
for (int i = 0; i < 3; i++) {
vColor += uPointLightingLocation[i];
}
片段着色器:
gl_FragColor = vec4(vColor, 1);
然后,如果您的多边形为黄色,则表示它正在工作。
Then, if your polygons are yellow you know it is working.
这篇关于将一组矢量传递给制服的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!