vishalchunne / blender-webgl-exporter

Automatically exported from code.google.com/p/blender-webgl-exporter
0 stars 0 forks source link

Error with "basic-native-example" #14

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago
1. Extract with 7-Zip on Windows 7
2. Open with firefox 4 on Windows 7
3. ERROR: 0:2: '' : No precision specified for (float) 

What happened?

Original issue reported on code.google.com by fernando...@gmail.com on 1 May 2011 at 4:23

GoogleCodeExporter commented 9 years ago
This cryptic error message is actually the fragment shader failing to compile 
properly, and can be fixed by adding the following three lines to the top of 
the shader-fs script (starting around line 12 of index.html)

  #ifdef GL_ES
  precision highp float;
  #endif

But that's not the end of the problems.  The handleLoadedTexture() function has 
a bad call in it:

 NO: gl.texImage2D(gl.TEXTURE_2D, 0, texture.image, true);
Yes: gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, 
texture.image);

Also, all instances of "WebGLFloatArray" must be renamed "Float32Array", and 
likewise "WebGLUnsignedShortArray" renamed to "Uint16Array".

The root cause of these issues is that index.html is based on an ancient 
version of the Learning WebGL lesson 5, written for last year's experimental 
half-baked WebGL implementations.  The WebGL standard has changed a lot since 
then, and in fact the Learning WebGL lessons have been updated, not only to 
comply with the new standard, but the author actually replaced the matrix 
library with a faster one, changed the animation from setInterval() to 
requestAnimFrame(), and made numerous improvements to the clarity and 
performance of the lessons.

So, someone should update the webgl-exporter and its examples to use the newest 
version of Lesson 5, or preferably the newest Lesson 14, which demonstrates 
loading a JSON object (which is not the same JSON structure as this script 
outputs, sadly).

Original comment by elm19...@gmail.com on 11 May 2011 at 8:39