topic Re: 2018 xgen custom shader parameter not working? in Maya Shading, Lighting and Rendering Forum

2018 xgen custom shader parameter not working?

jbrodskytd — Wed, 10 Jan 2018 17:12:19 GMT

Hi I'm fairly new to using Xgen and I'm trying to paint a custom color map to color my archive geo just like in this tutorial https://www.youtube.com/watch?v=L7XZxffWork

After I paint my map the geo displays and renders gray

here are the steps I'm taking:

create a plane
create a cube
save scene
create attach a description using custom geometry
create an archive out of the cube
add the cube archive file - now the cube is populated on the plane
go to the preview/output tab in xgen
under "custom shader parameters" create a color map
paint and save map
the cube geo renders and displays gray but you can see the color map on the plane geo

Am I missing a step? any help would be greatly appreciated!

Re: 2018 xgen custom shader parameter not working?

sean.heasley — Thu, 11 Jan 2018 19:52:01 GMT

Hi @jbrodskytd and welcome to the community!

Are you getting any errors in the script editor when this happens?

What renderer are you using? This tutorial was made for Mental Ray which is no longer supported with Maya 2018.

Also, did you set the project properly before starting this?

Let me know if anything changes!

Re: 2018 xgen custom shader parameter not working?

jbrodskytd — Thu, 11 Jan 2018 20:16:38 GMT

Hi Sean! thanks for the reply. I'm using arnold to render with.

I have a project and made sure it's set

I'll attach a zip file of the project the scene file is called color_test_001.ma if you wanna take a look

Thanks a bunch! I'm working n a project with a rattlesnake and I'm using xgen archive geo for the scales and I want to be able to paint the scale color patten... this is just a test of the process 🙂

I look forward to your reply!

-Jeff

Re: 2018 xgen custom shader parameter not working?

sean.heasley — Thu, 11 Jan 2018 20:37:54 GMT

Hi @jbrodskytd

I took a look at your scene file and for some reason it only showed the one cube and even when I loaded the archive it didnt fill the plane.

But before we focus on the xGen problem, I think I can help you with your project.

You said you were working on a rattlesnake? I'm curious as to why you would use xGen to color it as opposed to texturing it and/or using MASH to make the effect.

In fact, in the comments of that YouTube video the OP mentions using MASH. This tutorial may help you and should actually be a bit faster!

Re: 2018 xgen custom shader parameter not working?

jbrodskytd — Thu, 11 Jan 2018 20:57:03 GMT

wow that's super helpful! I initially tried using MASH but wasn't aware of how to control the color (outside of random colors) and how to use the offset node to control the scale of each "scale". That video is perfect thanks!

2 questions:

1.with the MASH distribute node I found I can either have the scales at each face center or at each vertex.. ideally I would have both to achieve that layered scale pattern. What I did was use 2 MASH nodes... one center of face and the other at each vertex. Is there a way to do this with one MASH node?

2. is there a way to mask off where the scales are populated? like I don't want them on the belly or parts of the head / face. i plan to use either textures or other geo for those areas

thanks a bunch!

Re: 2018 xgen custom shader parameter not working?

sean.heasley — Thu, 11 Jan 2018 21:07:57 GMT

Hi @jbrodskytd

I believe you would have to use two mash nodes but one thing you could do is actually model the scale and then create a second scale and place it underneath and/or attach it to the first one so it looks layered. Then you can simply combine them and make a MASH node out of them.

As for your second question, you could actually use the placer node to solve this! Here's a video on that tool!

If one or more of these posts helped answer your question, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

Kudos are greatly appreciated. Everyone likes a thumbs up!

Re: 2018 xgen custom shader parameter not working?

jbrodskytd — Thu, 11 Jan 2018 21:49:43 GMT

this is awesome thanks! I'll do a few tests with these techniques and let you know how it goes 🙂

Re: 2018 xgen custom shader parameter not working?

sean.heasley — Fri, 12 Jan 2018 15:29:16 GMT

Sounds good! I'll check in with you on Tuesday to see how things are going

Re: 2018 xgen custom shader parameter not working?

jbrodskytd — Tue, 16 Jan 2018 17:16:18 GMT

Hi Sean, thanks again for all the help!

I was able to use a MASH visibility node to control where the scales are. I also duplicated the repro mesh and applied a UV projection to the duplicate. I then used a transfer attributes to copy the UVs from the duplicate to the repro mesh. That way I could paint a custom texture map. It seems to work but looks like the transfer attributes goes wonky in a few frames.

here is a link to a vid of whats going on

https://drive.google.com/file/d/1pt9y4Obc6jxDD3H8zqhYOQNyS0vEAeBL/view?usp=sharing

Is there any way to bake the UVs into the repro mesh? Get rid of the live transfer attributes and avoid any pops?

thanks!

Re: 2018 xgen custom shader parameter not working?

sean.heasley — Tue, 16 Jan 2018 19:23:28 GMT

Hi @jbrodskytd

Have you tried deleting history?

If that doesn't work, you could try re transferring the map then deleting history. To do this you must find the original model in the attribute editor and uncheck Intermediate Object under Object Display. Then transfer the UV maps to this shape object and delete the history on it.

Let me know if this works for you!

Re: 2018 xgen custom shader parameter not working?

sean.heasley — Wed, 17 Jan 2018 19:08:25 GMT

Hi @jbrodskytd

I'm just checking in again to see if you need more help with this. Did the suggestion I provided yesterday work for you?

If so, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

Re: 2018 xgen custom shader parameter not working?

jbrodskytd — Wed, 17 Jan 2018 19:21:50 GMT

Hi Sean thanks for following up! I tried deleting non deformer history on the repro mesh but that didnt seem to work. I can't just apply UVs to the orig geo since that would result in all the scales looking the same. Any other ideas on how to map the scales as a whole?

Re: 2018 xgen custom shader parameter not working?

sean.heasley — Wed, 17 Jan 2018 20:04:24 GMT

Hmm Im not entirely sure cause the issue itself is weird that the UVs change for just a few frames but not throughout.

When you get a chance, can you please zip and attach the scene file here or via dropbox/google drive or another file sharing program so I can take a look at it?

Re: 2018 xgen custom shader parameter not working?

jbrodskytd — Wed, 17 Jan 2018 20:42:36 GMT

hi Sean here is the project

link

the scene file is

snake_scales_test_003.ma

Re: 2018 xgen custom shader parameter not working?

sean.heasley — Wed, 17 Jan 2018 21:37:29 GMT

Hi @jbrodskytd

Thanks for attaching the scene file!

I'm currently running a render of the animation to see if the issue is still present on my machine.

In the meantime, could you please try either changing or redoing the animation to see if the same issue occurs?

Its possible something went wrong when you set up the animation after transferring the attributes.

I'll be sure to let you know tomorrow how the render comes out on my machine!

Re: 2018 xgen custom shader parameter not working?

sean.heasley — Thu, 18 Jan 2018 21:11:45 GMT

Hi @jbrodskytd

Ah I found the culprit!

For some reason on a handful of frames your Uvs on the Repro Mesh get changed.

You may want to re do your UV snapshot and or your transfer of attributes to make sure you didn't miss anything!

Please let me know if this helps or if you need any more assistance!

If one or more of these posts helped answer your question, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

Kudos are greatly appreciated. Everyone likes a thumbs up!

Re: 2018 xgen custom shader parameter not working?

jbrodskytd — Thu, 18 Jan 2018 22:37:34 GMT

cool I'll give that a shot thanks for all of your help!

Re: 2018 xgen custom shader parameter not working?

shanianwer03 — Fri, 12 Feb 2021 21:44:05 GMT

Hi!

I'm using Maya 2018.5 and I have amd RX 580 8gb graphic card but I'm facing some fatal errors on rendering I'm using AMD render pro please help