This is a follow-up to my earlier post "WebGL doesn't have query objects" . Since I wrote that post, the situation has changed a bit. It's still true to say that WebGL doesn't have query objects, but the underlying reason - that OpenGL ES doesn't - is no longer true. For OpenGL ES 2.0 , there's an extension which provides basic query functionality: EXT_occlusion_query_boolean (which seems to have been based on ARB_occlusion_query2 from regular OpenGL). For OpenGL ES 3.0 , the functionality from that extension appears to have been adopted into the standard. The extension provides two query types, both of which set a boolean value to indicate whether any pixels passed the depth and stencil tests. While this is progress, unfortunately it's still not sufficient to implement the pixel accurate collision detection method I described in an earlier post. For that purpose it's not enough to know whether any pixels passed the tests; you want to kno...