Getting data from a render texture

[Joran]

Hello,

I want to get the data from a depth texture. I use the following command to create the texture:

depthtex = viz.addRenderTexture(format = viz.TEX_DEPTH, width = 8, height = 8)

And somewhere else I attach this texture to a viz.RENDER_DEPTH render node. Is there a way to get the data from this texture in python?

Greetings, Joran.

[farshizzo]

There is currently no built-in way to retrieve the data from a render texture. You could create a modifier plugin that attaches a post draw callback to the underlying osg::CameraNode object. From the callback you should be able to read the pixels from the texture into memory.

Do you need the data for real-time purposes (i.e. every frame)? If not, you can workaround the problem by rendering the depth texture to the screen and then capturing the screen to a file.

[Joran]

It is for real time processing. Is there any chance this functionality will be added in the future to Vizard?

Otherwise I will have to make that plugin. I am not looking forward to that.

[Joran]

I am revisiting this 'problem'. The version using a plugin did work (I need to recompile the plugin again). But now I saw the <multimedia:image>.saveToBuffer() method. It looks very useful. I still have:

depthtex = viz.addRenderTexture(format = viz.TEX_DEPTH, width = 8, height = 8)

And i can now save it to a buffer with:

depthtex.saveToBuffer('<raw>').

But this buffer then contains an 8 bit z-buffer. When I change my texture format to viz.TEX_DEPTH_32, I get the error message:

error pixelFormat = 81a7
** ERROR: Texture does not contain image data, cannot save to buffer

I am almost where I want to be. Is there some way to save a 16 bit or 32 bit z-buffer? Or maybe could the support for it be added to saveToBuffer?

Greetings, Joran.