Problem with Maya Layered Shader

[hanyou_kimura]

Hello, I'm new here. I was hoping that maybe I could get some questions answered regarding the Layered Shader in Maya 6.0.

I'm working on a rather large project for my senior year of college, and the modeling is finally complete, it's a car just so you all know. I have this really nice metallic blue layered shader I want to use but I've run into some setbacks.

When I tried tor ender it with Mental Ray the layered shader doesn't work right. Only the top layer shows up. I figured this is just one of those things that Metal Ray can't render and tried Maya Software. Indeed, it did work and looks great...but I ran into another problem. When I turn raytracing on I get the same problem where only that top layer works. It does work with Depth Map Shadows on though.

So here's my question, and maybe the answer is simple...with Depth map Shadows on, objects don't reflect off of one another, and I want them to. Is there a way to make them reflect or is raytracing or required? The other question is, do layer shaders only work with Maya Software and without raytracing? It may sound basic but I can't remember and can't seem to find the answer. Any help would be greatly appreciated. Thanks!

[agentxi]

raytracing is generally required, but you can also fake your reflections by using a reflection map...

as for layered shaders with raytracing it seems to work fine for me

would i be able to take a look at your shader and see if i can resolve your issue?

[hanyou_kimura]

Sure, how would I go about sending it to you? Do you mean th actual shader or a render of the model with the shader?

[agentxi]

all of the above, I sent you my email through a pm, but if you could attach a render of the error, that would help decipher the issue some. and if you could let us know what your render settings are for mental ray that would be great. Like are you using Global Illumination or Final Gathering, what your reflection bounce limit is or refraction limit is, etc.

[hanyou_kimura]

Alrighty, so here is the shader rendered in maya software without raytracing:



My problem with it is that while it looks nice teh shadows are weird...I dunno if it's my model or what but when used with a regular blinn material it's fine.

Here's it with raytracing on:



Only the top layer of teh shader shows up...this is teh same result with mental ray.

Now here is the car with maya software with raytracing with blinn:



And here is thesame material only red with mental ray:

[agentxi]

hmm, that's a tough one without actually seeing the shader in front of me.

My guess would be to troubleshoot some of the following.

When you are raytracing there are limits to how many raytraces that maya will calculate. By default it is 1. I would change this to 3 or 4 for now and see if it will render any differently. Just keep in mind that if you crank it too high, it will freeze your system, as the higher the number for this, the more resources it will eat. (if the raytracing reaches it's limit it will render the rest as black and same with refraction settings)

If it does not, then I would go onto the lights themselves. Turn up the intensity of the lights and see if that makes a difference.

Also remember when rendering with Mental Ray, to go inside the Render Globals, to go into the Common tab, and turn off "Enable Default Light" as this default light messes up your lighting some.

[syrtyr]

you should be sure that your lighting is right...., with ray tracing and globals maya will take one light and use it like regular light....., from what I was taught if you try to use to much lighting with mental ray and ray tracing it will mess with the shaders