webgl2

问题 Different from OpenGL ES 3, without gl.mapBufferRange and gl.bufferSubData (It exists), what is the efficient way to update uniform buffer data in WebGL 2? For example, a PerDraw Uniform block uniform PerDraw { mat4 P; mat4 MV; mat3 MNormal; } u_perDraw; 回答1: gl.bufferSubData exists so it would seem like you create a buffer then create a parallel typedArray. Update the typedArray and call gl.bufferSubData to copy it into the buffer to do the update and gl.bindBufferRange to use it. That's

问题 Looking for some patterns/code examples/best practices of appropriate usage of fences in webgl2 (gl.fenceSync) - best if it would be non blocking of JS thread. var fence = gl.fenceSync(gl.SYNC_GPU_COMMANDS_COMPLETE, 0); setTimeout(() => { gl.clientWaitSync(fence, gl.SYNC_FLUSH_COMMANDS_BIT, 1000000); gl.getBufferSubData(gl.TRANSFORM_FEEDBACK_BUFFER, 0, dataOut); }, 0); 回答1: I'm just guessing to be honest, I'm not actually sure how useful syncs are in WebGL2 but I'd think you don't want to

问题 Please refer to the background section below if the following does not make much sense, I omitted most of the context as to make the problem as clear as possible. I have two WebGLRenderingContexts with the following traits: WebGLRenderingContext: InputGL (Allows read and write operations on its framebuffers.) WebGLRenderingContext: OutputGL (Allows only write operations on its framebuffers.) GOAL : Superimpose InputGL's renders onto OutputGL's renders periodically within 33ms (30fps) on

问题 In the example page at https://www.lighthouse3d.com/tutorials/glsl-tutorial/uniform-blocks/ has this: uniformBlockBinding() bindBuffer() bufferData() bindBufferBase() But conceptually, wouldn't this be more correct? bindBuffer() bufferData() uniformBlockBinding() bindBufferBase() The idea being that uploading to a buffer (bindBuffer+bufferData) should be agnostic about what the buffer will be used for - and then, separately, uniformBlockBinding()+bindBufferBase() would be used to update those

问题 Problem Description Hi! In our WebGL application, we are drawing many (even hundreds of thousands) shapes and we want to discover which shape is currently under the mouse. I'm looking for a way to do it in an efficient manner. Details The shapes are defined with Signed Distance Functions. Each shape is drawn by applying a predefined sdf fragment shader to a square polygon (2 triangles). Each shape is assigned with a unique ID ( uint ) on the Rust side (we're using WASM here). The idea is to

问题 Problem Description Hi! In our WebGL application, we are drawing many (even hundreds of thousands) shapes and we want to discover which shape is currently under the mouse. I'm looking for a way to do it in an efficient manner. Details The shapes are defined with Signed Distance Functions. Each shape is drawn by applying a predefined sdf fragment shader to a square polygon (2 triangles). Each shape is assigned with a unique ID ( uint ) on the Rust side (we're using WASM here). The idea is to

来源： https://stackoverflow.com/questions/56779164/why-unbind-gl-uniform-buffer-before-calling-bindbufferrange

来源： https://stackoverflow.com/questions/56779164/why-unbind-gl-uniform-buffer-before-calling-bindbufferrange

问题 Ok I'm going to keep this as simple as possible. I want to pass data between shader programs. I'm using readPixels currently to do that but I feel it may be slowing operations down and I'm exploring faster options. what my program does: program1 does my rendering to the canvas. program2 does some wonderful operations in it's shaders that I want to pass to program1. MY QUESTIONS: is it possible to use the vbo from program2 and pass that to program1 for rendering? From what it sounds like in

问题 I want to rotate and translate a 2d shape made with signed distance functions. The docs say this is the method: vec3 opTx( in vec3 p, in transform t, in sdf3d primitive ) { return primitive( invert(t)*p ); } It looks to me like primitive is some kind of function (or a struct) I can call, Is there a way to pass functions like that (or how does this make sense)? Firstly I don't know what transform and sdf3d types are, and what is the invert function. Secondly how do I apply this to 2d? const