Brandon Allen


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Recent Forum Posts

HDA processor parameter referencing 2020年3月26日18:41


HDA Processor is not actually cooking the instances of the HDAs that are within your HIP file. When an HDA Processor job cooks, it runs Hython in a new process. The HDA Processor job will instantiate the HDA within that Hython session, set the parameters, cook the HDA, and then report the outputs. Therefore, if you want to expose the HDA Parameters on the interface of your top-level OBJ HDA, I would directly promote the HDA Parameters from the HDA Processor onto the top level HDA interface.

I will file a bug for the hide/disable not working. This is happening because the HDA Parameters are prefixed to avoid name clashes and the hide/disable expressions are not updated to account for this.

Buttons on your HDA's interface should be working correctly. They will appear as Toggle parameters within the “HDA Parameters” folder. When the toggle is enabled, it means that HDA Processor will “press” the button when it cooks.

You are correct – the “Enable Expressions” toggle in the “Filter HDA Parameters” window is just a quick way to enable Python expressions on parameters.

You could drive everything on the HDA Processor using attributes like you are describing. I would recommend disabling all the parameters with the “Filter HDA Parameters” window if you do this. The HDA Processor knows which attributes on the work item are HDA Parameters via 4 string attributes: hdparms_buttons, hdaparms_floats, hdaparms_ints, and hdaparms_strings. These attributes contain lists of names of the HDA Parameters. For example, if you wanted to set a float attribute on your HDA Processor called “velocity”, you would have to add a “velocity” attribute with its values, and add “velocity” to the hdaparms_floats string attribute.

I hope this helps. Let me know if you have any more questions. I can also provide some example files if you need any further clarification!

max houdini engine start session error 2020年3月16日17:46

Hi there,

Can you submit a bug for the problem with the session not successfully starting when not using an administrator account? A bug can be filed here: []

Thank you!

Passing attributes 2020年2月14日19:33

The plugin should be able to import alpha, illumination, as well as all of the uv maps (uv..uv99).

I tried to reproduce the crash with the attached asset but was unable to. I also tried changing uv11 to illumination, but the illumination was showing up correctly in 3ds Max.

I will try a few more tests (I was investigating with 3ds Max 2019 but I will also try with 2018), but if you could also attach the HDA that is crashing for you, that would be super helpful!

Thank you!