topic Re: Lighting a motion capture model in Arnold in Maya Shading, Lighting and Rendering Forum

Lighting a motion capture model in Arnold

saundersj7PB45 — Mon, 18 Mar 2024 19:01:30 GMT

Hello. I have taken an FBX motion capture file that was exported from Motive (Optitrack product) and imported it into Maya. I've figured out how to import a separate FBX model of a generic man figure and attach the skin of the model and the motion capture file so that the model does the moves of the motion capture actor.

I also figured out how to export the project as an image sequence so that it can be uploaded to a program such as Nuke to do video compositing. However, the export was black. I found some tutorials on lighting a scene in the Arnold renderer and have the model somewhat lit. I made the light much bigger to compare to the size of the model I am trying to light. But, the model is not fully lit and doesn't change no matter how much I adjust the intensity and exposure.

First, do I need to use the Arnold renderer to render this file? If not, will the scene automatically be lit?

If I do need to use the Arnold renderer, are there any tutorials on lighting a scene the correct way with the Arnold renderer? One video says to add Arnold materials to the item I am trying to light. However, because the file is actually two different files, I'm not sure which one to add the materials to.

I am new to Maya. I've got a basic understanding of Nuke and how to bring in a file that has been exported from Maya. But, I'm just having trouble getting the model lit correctly in Maya before exporting it as the image sequence. Any help would be greatly appreciated. Thanks.

Re: Lighting a motion capture model in Arnold

Christoph_Schaedl — Tue, 19 Mar 2024 10:22:02 GMT

There are plenty of tutorial about on youtube.

https://www.youtube.com/@arvidurs/videos

Beside that the easiest way to get a basic lighting is to use an HDRI.

Do some research first and come back if you need extra help.

Re: Lighting a motion capture model in Arnold

Christoph_Schaedl — Tue, 19 Mar 2024 10:23:32 GMT

This one could give you a good start.

https://youtu.be/8sU7k_sBKH4?si=jVjL49kXsWLLO2Bm

Re: Lighting a motion capture model in Arnold

saundersj7PB45 — Tue, 19 Mar 2024 14:28:17 GMT

I did some of the steps in the first half of the video and it still looks the same. I wasn't quite sure how he got to the window where he started adding the subsurface options. But, those looked to just be making the image a little sharper. I have attached two screenshots. One shows the light and the model in the scene with the selections made to the Arnold areaLight's exposure and color temperature. The other screenshot shows what it looks like in Render View. Thanks again.

Re: Lighting a motion capture model in Arnold

saundersj7PB45 — Tue, 19 Mar 2024 17:51:06 GMT

I'm having some success. I didn't realize that numbers could go higher than the slider. After looking at a post of somebody who had a similar issue, one of the suggestions was to use a sky dome light to light the whole scene. So, I deleted the other lights and added the sky dome light. I got the result in the screenshot attached.

When this renders, will it just be the model or will the entire white background show up? Thanks again.

Re: Lighting a motion capture model in Arnold

Christoph_Schaedl — Tue, 19 Mar 2024 18:09:12 GMT

In the light turn down the camera samples to zero and the background will be black and not visible in thr alpha.

Re: Lighting a motion capture model in Arnold

saundersj7PB45 — Tue, 19 Mar 2024 18:24:00 GMT

Do you mean the camera visibility?

Re: Lighting a motion capture model in Arnold

Christoph_Schaedl — Tue, 19 Mar 2024 18:28:34 GMT

Re: Lighting a motion capture model in Arnold

saundersj7PB45 — Tue, 19 Mar 2024 18:35:28 GMT

So, this should now just show the white model by itself when I render it and eventually import it into a program like Nuke? Thanks again.

Re: Lighting a motion capture model in Arnold

saundersj7PB45 — Sun, 24 Mar 2024 14:31:58 GMT

I believe I did get the answer I needed. I'm in the process of trying to composite the clip over a regular video clip in Nuke. The regular .mov clip is giving me an error in Nuke so I can't yet see what the motion capture exported from Maya looks like. But, from what I can see so far in Nuke, it looks like it is just the model that is showing up. I'll know what it looks like for sure once I get the .mov error figured out in Nuke. Thanks.

Re: Lighting a motion capture model in Arnold

Christoph_Schaedl — Sun, 24 Mar 2024 15:06:25 GMT

Dont use .mov.

Render to exr files. Exr is the file format nuke is build around.

Re: Lighting a motion capture model in Arnold

saundersj7PB45 — Mon, 25 Mar 2024 12:53:41 GMT

Would I need to convert each .mov file to .exr to be able to use it in Nuke? Thanks again.