Houdini, NodeSwitcher and Displacement.

Sat Nov 24, 2018 11:34 pm

I need to switch between 2 nodes inside a HDA, and Octane has the ‘NodeSwitcher’ to switch.

But Houdini does not recognize the NodeSwitchers input and output pinns datatype and basically destroys the HDA if you try to connect it out (luckeliy I have backups).

I want to switch between 2 displacement nodes, and thats the only way I have managed to switch between 2 displacement nodes. but not inside a HDA obviously.

I thought maybe I could put a MixTexture instead, but _any_ type of node between a regular ‘Texture Image RGB’ and ‘NT_Displacement’ will not work. with the exception of the NodeSwitcher, when in turn breaks the HDA’s. Despite everything saying it is “color” data type.

I have attached 2 images showing that the multiply node eats up the displacment. Unfortunatly it is hard to show the other problem where the NodeSwitcher destroys HDAs because well…it destroy the HDAs =)

Sun Nov 25, 2018 6:54 pm

MagnusL3D wrote: But Houdini does not recognize the NodeSwitchers input and output pinns datatype and basically destroys the HDA if you try to connect it out (luckeliy I have backups).

Sorry, but this is something that I can't reproduce here. The HDAs with the node switcher inside work fine here. In fact, for example, the current Render Target HDA has a lot of these nodes. What are the exact steps to reproduce this problem?

About the mix texture node and displacement, I'm afraid that currently the displacement only works with the texture image node linked directly to the displacement input. No other nodes are compatible with this feature.

Thanks,
-Juanjo

Sun Nov 25, 2018 8:40 pm

juanjgon wrote: Sorry, but this is something that I can't reproduce here. The HDAs with the node switcher inside work fine here. In fact, for example, the current Render Target HDA has a lot of these nodes. What are the exact steps to reproduce this problem?

I think it happens when yo already have a HDA with a data output set to a say "color" and you replace it with the node switcher. I am not sure the Render Target HDA is a good test since it doesnt have to deal with the output pins coming out correctly as you have to when you build a HDA to build shader networks within the octane material builder.
I can't make easy reproduction of this since you need the HDA in a edit state and i don't know how to send that over in a proper fashion. If you have any ideas let me know.

However I have come up with another approach and do not need the switcher currently. houdini python to the rescue.

juanjgon wrote: About the mix texture node and displacement, I'm afraid that currently the displacement only works with the texture image node linked directly to the displacement input. No other nodes are compatible with this feature.

You can actually use the bake tool in between =) But yeah..I just dislike that they state that their data type is color, because then it should be compatible with everything else that is of the type color, but they are not.

/Magnus

-Juanjo

Mon Nov 26, 2018 11:19 am

Ah, yes, of course, the bake tool should work, in fact, it is there to help with the displacement from procedurals and so on.

About the switcher node use as an output, yes, perhaps this doesn't work. I need to test it. This node is not a native Octane node at all, it is only an internal node used as a hack to make possible de configuration of complex node trees, like the Render Target HDA, selecting the input node to be used at extraction time, but it doesn't work like any other Octane node, and its pin types are generic ones.

Thanks,
-Juanjo

Mon Nov 26, 2018 2:20 pm

Allright let me know if and how I can help, it's a bit hard as previously mentioned to send a test scene for this special case but I will do what I can if you have any ideas.

Thu Dec 06, 2018 3:08 pm

Hi,
Is there any chance we could get the mix node working with Displace ? Or is there another workaround ?
Baking is not an option unfortunately for me as I'm already using the 3 uv sets (it's on a flip sim).

Thanks !

Fri Dec 07, 2018 10:04 am

HMXMedia wrote:Hi,
Is there any chance we could get the mix node working with Displace ? Or is there another workaround ?
Baking is not an option unfortunately for me as I'm already using the 3 uv sets (it's on a flip sim).

Thanks !

I'm afraid that this is an Octane core limitation, that I'm not sure how easy is going to be to resolve it in the near future. The baking type workarounds are the only solution currently.

Thanks,
-Juanjo