Updating material

I have here UE 4.26 project imported to Machinima.

Now I need to make these bulp lamps to be luminous.
I thought the easiest way is to make the material assigned to them a semi trasparent and then just lay out some lamps inside those bulps in Machinima, using native lights.

I know that I cannot edit the imported UE material parameters in Machinima, I have to use UE for that. But my question is:
How this is meant to be “dynamically connected” - If I just re-write the USD file with “export to Omniverse” then I lose the adjustments I have made to my circus project in Machinima.

So is my only option to drag the converted USD circus to a fresh new Machnima project called “Machinima Circus”, and then do my scene: camera, light % animations there. And then if I edit the materials some other day again in UE, I just export to omniverse and over-write that circus USD and the changes are naturally reflected to the “Machinima Circus” USD project.

Correct?

I know that if I drag a USD file to a fresh “Machinima Circus” USD project, then I cannot access all editing features of the assets in it. What are these features?

There are multiple ways to do this. If you select the bulb mesh and click on the arrow to the right of the mesh section’s material reference it will take you to the material. If it was designed to be emissive there will be a control there. (You can indeed edit imported UE material parameters in Machinima when they exist. They will save with the stage.)

If it was not designed to be emissive you can recreate the material on that section of the mesh. Take note of the textures used on that mesh section’s material, you’ll be reusing them. Depending on how they’re designed you will also be downloading one for using as the basis of a new texture in Photoshop or similar.

Note that I’m assuming the UE material is created in the most common way. Read through the steps first and look at the textures to see if you think this will work. If not reply with some more details and we’ll see what we can do.

  1. Right click on the bulb mesh and select Create>Materials>OmniPBR.
  2. Place the textures you noted earlier in the appropriate slots of your new material.
  3. Locate the “Emissive” section of your OmniPBR material and enable it. Set emissive color to white.
  4. Load the texture containing the bulb colors into “Emissive Color Map.”
  5. Look at the thumbnails of the relevant textures and choose the one that most clearly indicates a distinction between the bulbs and the bases of the lights. Download it and load it into your image editor.
  6. Create a mask by selecting the bulb areas of the texture. Fill it with white. Invert the selection and fill it with black. Save with a new file name, upload it, and apply it to the “Emissive Mask map.”
  7. Adjust the emissive intensity. It will probably need a very high value. If you’re using real time mode be sure to enable indirect diffuse GI in render settings.

You should now see emissive bulbs. Let us know if this works.

Looks like it was not designed to be emissive. I cannot edit anything with that material in Machinima, right?

No, if the material did not have adjustable parameters in UE4 it will not have them in Omniverse. You can, however, create a brand new material in Machinima and use the existing textures as described above.

1 Like