PYOPENGL_PLATFORM = osmesa not working with DEPTH_ONLY flag

[ericvg97]

I am running the second example code from the quickstart changing/adding this part of the code:

flags = pyrender.RenderFlags.DEPTH_ONLY | pyrender.RenderFlags.OFFSCREEN
depth = r.render(scene, flags = flags)

And it works fine. However, when I ask it to work with OSMESA at the beginning of the code with:

import os
os.environ['PYOPENGL_PLATFORM'] = 'osmesa'

I get the following error:

Traceback (most recent call last):
  File "prova3.py", line 30, in <module>
    depth = r.render(scene, flags = flags)
  File "/usr/local/lib/python2.7/dist-packages/pyrender/offscreen.py", line 101, in render
    self._renderer.render(scene, flags)
  File "/usr/local/lib/python2.7/dist-packages/pyrender/renderer.py", line 140, in render
    retval = self._forward_pass(scene, flags)
  File "/usr/local/lib/python2.7/dist-packages/pyrender/renderer.py", line 322, in _forward_pass
    self._configure_forward_pass_viewport(flags)
  File "/usr/local/lib/python2.7/dist-packages/pyrender/renderer.py", line 979, in _configure_forward_pass_viewport
    self._configure_main_framebuffer()
  File "/usr/local/lib/python2.7/dist-packages/pyrender/renderer.py", line 1061, in _configure_main_framebuffer
    self.viewport_width, self.viewport_height
  File "/usr/local/lib/python2.7/dist-packages/OpenGL/platform/baseplatform.py", line 409, in __call__
    return self( *args, **named )
  File "/usr/local/lib/python2.7/dist-packages/OpenGL/error.py", line 232, in glCheckError
    baseOperation = baseOperation,
OpenGL.error.GLError: GLError(
	err = 1282,
	description = 'invalid operation',
	baseOperation = glRenderbufferStorageMultisample,
	cArguments = (GL_RENDERBUFFER, 4, GL_RGBA, 400, 400)
)

This would be useful for anyone wanting to work via ssh and without the need to render color (which is particularly our case)

Thank you!

[bolitt]

I got the same issue at Line 1091 of renderer.py.

Furthermore, I checked GL_MAX_SAMPLES

glGetIntegerv(GL_MAX_SAMPLES)  # returns 1

However, the spec said it should be at least 4, which is quite weird.

-- Notes --
If I changed Line 1091 and 1096 from samples = 4 to 0. The result will be all empty images.

[bolitt]

[Update]
For the error, my fixture is at Line 1091 and 1096:

num_samples = min(glGetIntegerv(GL_MAX_SAMPLES), 4)   # No more than GL_MAX_SAMPLES
glRenderbufferStorageMultisample(GL_RENDERBUFFER, num_samples, GL_RGBA, self.viewport_width, self.viewport_height)
glRenderbufferStorageMultisample(GL_RENDERBUFFER, num_samples, GL_DEPTH_COMPONENT24, self.viewport_width, self.viewport_height)

For the problem of empty images, I also use explicit flags. After digging into the offscreen.py, I find RenderFlags.OFFSCREEN is added automatically, so there is no need to explicitly use RenderFlags.OFFSCREEN in flags.

if self._platform.supports_framebuffers():
    flags |= RenderFlags.OFFSCREEN
    ...
else:
   # If your platform doesn't support framebuffers, it cannot render with `RenderFlags.OFFSCREEN`.
    ...

So argument flags should not contain RenderFlags.OFFSCREEN.

It solves my problem. Hope it helps!