FX-Map breaks when driving Iterate with a parameter at graph level

[Pablo Couto]

I'm having trouble trying to drive the Iterate node inside an FX-Map with a parameter at graph level. Please see the attached SBS file(*). I connected the Iterations parameter on the Iterate node to the `iterations` integer parameter at graph level. Making the connection, though, seems to break the FX-Map node: the output looks incorrect, or simply black, after changing the value of the `iterations` parameter a few times. When controlled directly from the Iterate node, however, the FX-Map works as expected. The screenshot below shows the expected result.

Using Substance Designer 10.2.1 build 4191 / Windows 10 2004 build 19041.1052.

(*) Please remove the `.xml` extension from the SBS file. The attachments function doesn't allow SBS.

[gaultvincent]

Hey, I can reproduce: sharing with the dev team

[gaultvincent]

Hey it comes from the fact that you are trying to get a 'prev' variable, that you 'Set' after in your graph + when you set a variable, you have to use a sequence node in order to both output the result the output of your graph and the new set variable.

[Pablo Couto]

Thank you for your message. I tried setting it as shown in the screenshot, but it didn't solve the issue. I continue to get broken outputs, and now the application also freezes intermitently, forcing me to kill Designer.

I unmarked the "Correct Answer" on your post as it's not working for me. Attached is the updated file with your suggested change.

 

[Luca Giarrizzo · Accepted solution]

Hello,

The Sequence node needs to be set up in the Iterations parameter of the root Iterate node in the FX-Map graph, as shown below.

Function graph of the Iterations parameter

This node will be processed first when evaluating the FX-Map node, thus the prev variable will be initialised through this parameter so it is ready to be accessed in the Function graph for the Quadrant node's Pattern Size parameter.

This technique is commonly used to initialise variable for later use. Similarly in the Pixel Processor node, the Output Size parameter is a safe place to initialise variables.

[Pablo Couto]

Thank you, Luca. That worked perfectly.