Hello,

I can't understand how to work with filepattern.

I manage to load multiple images using filepattern.
But how to pass those to ropcomposite1?

For ex, I want to convert multiple exr to png.
I get this error.

Thanks

The file pattern node creates work items with files listed as outputs for that work item. In order to reference them, the downstream node needs to use the @pdg_input variable or pdginput(..) function in an expression. When cooking with a ROP Composite TOP, ROP Geometry, etc you can use PDG expressions on the nodes cooked by the ROP as well.

If you're running into a specific issue, please upload a .hip file so that someone can take a look.

Thank you for your help

Here is the zip archive with the hip and 3 exr files that need to be converted to png or alternatively used with ffmpeg to generate a video. What should be the approach?

In order to use the FFMPEG node, you need all of the files to be listed on a single work item. You can do that in one of two ways -- either put a wait for all after the file pattern, or uncheck "Split Files into Separate Items" on the file pattern. Your .hip file also has an FFMPEG Extract Images node, which is for converting a video file into images. You probably meant to use FFMPEG Encode Video instead, which creates a video from images.

For the ROP Composite, set the output path to something like $HIP/png/`@filename`.png. That allows you to rename the file from a .exr to .png, using the same file name as the input.