Separate Render Channels Gamma settings on a Batch Render

V-Ray V-Ray for 3ds Max Issues
1

When rendering separate render channels with a batch script the gamma settings are not applied to the output (tif in this case)
If i render within 3dsmax the gamma is applied to the output images just fine.

I set all the settings with maxscript ‘-script’ argument.
I’m not quite sure how to apply the gamma to the output. here is an example:

OutputPath = "C:\\temp\\File.tif"
MyBitmap = Bitmap renderWidth renderHeight filename:OutputPath gamma:2.2

Now i can set

renderers.current.output_splitfilename = MyBitmap.filename

But it will not use the gamma settings stored in ‘MyBitmap’
The ‘.output_splitbitmap’ requires me to ‘save’ first which does not work in my case since it’s a pre-render script.

What am i missing? :slight_smile:

2

Looks like i found another problem related to ‘Separate Render Channels’ in a batch.

If a filename is never manually selected as an output it will not save the images if the output is set via maxscript in a batch.
the ‘raw image file’ works but not the separate channels.

setting it manually must be triggering something that the maxscript does not.
it’s an easy workaround but gave me some grey hairs to figure out.

3

this is still a bug in the latest version.

4

This is a 3ds Max thing. Quoting this page:
“As mentioned above, the render() method does NOT use the current render settings found in the Render Scene Dialog. Thus, calling render() will NOT save to the output file name specified in the Render Scene Dialog or via the rendOutputFilename global, but will use the output specified via the outputfile: optional parameter and/or simply return a bitmap value.”

Since V-Ray’s “Separate Render Channels” utilizes the 3ds Max output, and it in turn can output only through render outputfile:“”, the workaround is to save the images from the VFB or use the method from the post below. Sample script for 3dsmaxbatch


scenePath = @"G:\\path\\test.max"
OutputPath = @"G:\\path\\\\File.tif"
loadMaxFile scenePath useFileUnits:true quiet:true
Render()
vfbcontrol #saveallimage OutputPath

This, of course, is the method for doing it solely through MaxScript. The manual method, as you mentioned, is also valid.

Regarding your original post: maybe it was the “comma” vs “dot” issue for the gamma application, similar to this thread.

5

EDIT:

The devs actually shared a way to do this without the need to save from the VFB. What you (and I) were missing is the “saving” of the temporary bitmap and later assigning via .output_splitbitmap. Yavor described the method in this thread and in this thread.