Differences between texture2d and texture2dproj under webgl1.0

  Conclusion ：

webgl in texture2D and texturre2Dproj The difference ：
 

    1. texture2D and texture2DProj The difference is that texture2DProj The interior will be divided by coord Last component of ;
    2.  Use texture2DProj Texture free GL_TEXTURE_COMPARE_MODE, So as to obtain the depth for comparison ;
    3. webgl1.0 Failed to set on my host GL_TEXTURE_COMPARE_MODE Parameters ,
        Whether it is webgl1.0 It is not clear whether it is not supported by the local browser ？

Recent learning webgl In the programming guide shadowmap, Use it texture2D and texture2DProj Conducted in-depth study at the same time , It also deepens the understanding of the projection matrix and its homogeneous coordinate system w Understanding of weight . Some specific reference links are as follows ：

  About W The meaning of components can be derived from matrix ：https://blog.csdn.net/stl112514/article/details/83927643
     Projection texture ： https://blog.csdn.net/e295166319/article/details/56012831 
     Projection texture ： https://zhuanlan.zhihu.com/p/62096266
    shadowmap： https://zhuanlan.zhihu.com/p/61237722

 

I learn shadow.js  meanwhile , Use texture2Dproj It's done shadow_texture2DProj Modification test of

shadow.html

Shadow_texture2DProj.html