WideAngleCamera cube map texture pixel format should be customizable

[scpeters]

The rendering::WideAngleCamera::CreateEnvRenderTexture function creates an envCubeMapTexture using the same pixel format as the output image. For advanced users who write their own shaders, it can be necessary to use a floating point pixel format for the cube map texture even if the output image uses integers, for example to avoid integer overflow. I think it would be convenient to specify this in SDFormat as a env_texture_format parameter that is a sibling to the //camera/lens/env_texture_size element.

[scpeters]

Intending to target this at gazebo9 and gazebo11

[iche033]

the proposed approach should work. One thing to note is that with //camera/lens/env_texture_size we're getting into implementation details on internal / intermediate texture formats. I'm not sure if the param would be useful other consumers of sdformat since they may decide to implement wide angle cameras differently.

Other options include:

• setting the format to Ogre::PF_FLOAT32_RGB here in gazebo classic and wide angle cameras should still work - it just uses more memory.
• Provide a WideAngleCameraClass::SetEnvTexFormat function for users to set through plugins. The downside of this approach is that we'll need to recreate the env textures when users sets a different format.

[scpeters]

• setting the format to Ogre::PF_FLOAT32_RGB here in gazebo classic and wide angle cameras should still work - it just uses more memory.

I'll try this and see if I can quantify the memory impacts

[scpeters]

• setting the format to Ogre::PF_FLOAT32_RGB here in gazebo classic and wide angle cameras should still work - it just uses more memory.

I'll try this and see if I can quantify the memory impacts

I tried this earlier today with a pair of wide-angle cameras with 2048x2048 resolution with a target update rate of 30 Hz. When using the same intermediate pixel format, I was able to reach 30 frames per second easily, but when using FLOAT32 for the cube map texture, it dropped the frame rate by a factor of 10 to less than 3 frames per second. According to nvidia-smi, it also increased the GPU memory usage of gzserver by a little over 1 GB, but I think the performance hit is the most significant factor.

This will need to be configurable.

[scpeters]

I'll try adding an API for plugins as well as a custom namespaced element like //camera/lens/gazebo:env_texture_format

[scpeters]

I've created a branch that sets the texture format based on the custom element //camera/lens/gazebo:env_texture_format in scpeters@d3793e3

In terms of adding an API for setting the texture format programmatically, is it possible to change the texture after the camera has been initialized? This seems a bit more complicated to me

[iche033]

I think you'll need to remove the existing texture and then create a new one with the new format