Accessing viewMatrix in main program

Questions
1

Hi, I need to access viewMatrix in the main program to compute another matrix(called cameraToLightSpace) that transforms the point from camera to light space. I then pass cameraToLightSpace matrix to the shader, because making this computation in the shader would be more expensive. How do I access viewMatrix in the main program and also ensure it is updated each draw call?

The equation I am using for the computation:
cameraToLightSpace = lightProjectionMatrix * lightVIewMatrix * inverse(viewMatrix);

Also I am using glMatrix API for these matrix computation. Is there a more efficient way to do the same?

1 Like
2

Are you looking for this? https://threejs.org/docs/index.html#api/en/renderers/webgl/WebGLProgram

// = camera.matrixWorldInverse
uniform mat4 viewMatrix;
1 Like
3

If you need the view matrix in JS, it’s Camera.matrixWorldInverse.

3 Likes
4

Yes, Thank you !

5

Thank You !