Solved: Re: Bifrost & Standard Surface applied to default shading group cause major issues...

slimboJoe · ‎09-12-2023

Is anyone else having issues with Bifrost & Standard Surface applied to initial shading group? I'm using Maya 2024.1 with an nVidia 3070 and driver 536.23. Newest Bifrost of 2.7.0.1.

I cannot get Bifrost particles to color correctly in the viewport or the render. Hooking a set_property node to source_particles to color the particles has no effect in the viewport. Using an assign_material node with the material having an aiUserColorData node reading the set_property color data does nothing for the render. Just using the assign_material with a regular color on the material provides unpredictable results in the viewport if it DOES decide to display. Just clicking the color slider on the material will cause the particles in the viewport to suddenly go back to grey. Repeated clicks (without changing value) cause the particles to swap between grey and the material color. Then Maya crashes.

I can load a scene from Maya 2020 into 2024 and it works as expected. Making a scene from scratch in 2024 yields very poor results.

I'm really upset because I just decided to learn Bifrost and started in 2024.1, but none of the tutorials work because of this issue and some other changes implemented in the wording and ports of the Bifrost Graph. I've spent hours trying to figure out what I'm doing wrong, only to find it's seems to be the currently version of Maya at fault.

Any help or insight would be great appreciated. I can provide basic examples scenes if necessary.

sepu6 · ‎09-13-2023

Can you share the scene where you are having issues? Easy to help and debug.

slimboJoe · ‎09-14-2023

Sure. Attached is a simple scene file. I left the standardShader1 material attached to the defaultShadingGroup. If the lambert1 material is plugged into defaultShadingGroup, it sort of works. Unhooking the set_geo_property_reference node from the assign_material node in the Bifrost graph makes the viewport work as expected, but then the render is wrong. To coordinate the render (final output) and the viewport takes just the right combo of node connections and random selections, and even then it will sometimes revert back to no color.

The two movies show the main issue and then how just selecting materials in the Hypershade will cause the viewport to randomly work or not.

sepu6 · ‎09-14-2023

Okay, so a few things here.

The `set_geo_property_reference` node is used when you create a standard material inside the graph not when you bring it from the hypershade since you are using a user data color.

The user data color is reading the data from BF on the shading network, so you use the material reference directly.

I added an example of how to use the set geo property reference. (take a look at the node parameters)

If you want to see the point color on the viewport use an `assign diagnostic material`. On the emission color I'm using the property (color) that is coming from the particle, the same that you are using everywhere else. The ports that look like hats are auto ports meaning that you can connect strings, vectors, float, fields, etc. which is super useful.

Here is the file working fine.

slimboJoe · ‎09-14-2023

So this all changed from previous versions? The file setup works as expected in Maya 2020 and is a standard technique in several tutorials that I was learning from.

sepu6 · ‎09-14-2023

it changed because now the standard material is the default, so yes.

However what you were doing with the `set_geo_property_reference` was wrong. That never worked like that.

And when you are bringing material with `user data` from the hypershade that always has worked like that, there is not need for a set geo property reference.

slimboJoe · ‎09-14-2023

Seems to function like I would expect! Thank you, thank you, thank you!

Where did you learn Bifrost? The Maya tutorials seem outdated in many ways and other tutorials I found online steered me into rough waters apparently. Seemingly simple things like output should be built in or fool (me) proof.

Thanks again! I'm marking this as a solution.

slimboJoe · ‎09-14-2023

I really just started learning Bifrost 5 days ago, using outdated and incorrect tutorials because Maya's docs are somewhat lacking. Are there some good docs or tutorials that teach these very basic setups, like viewport and rendering output? It seems like it should just work without adding in diagnostic material nodes and such.