Rendering glossy materials in Alias... HALP!


I’m really struggling on making my shaders glossy/reflective. I want to have my materials reflect what’s around them (other materials, shadows, environment), but I have no idea how to do this. I’ve looked through some books and I really need some help.

I’ve attached a screenshot showing what it currently looks like + some of the settings. Any tips would be greatly appreciated.

start by using one of the default rendering environments. The black and white stripy one is a good starting point to get shiny stuff looking shiny. It can be found in the Environments tab in the visualization mode of the side control panel.

Turn off “use Environment” . That seems to be mainly a setting used for hardware shade. for Software rendering, that is telling the raytracer to only use the environment to reflect. with that off, it will reflect everything including the env.

your image looks really nice. cant tell, but make sure you pre-compute ambient occlusion for the best look.

Tangerine: You have to describe what you are after a little bit more. I notice your shader has a bump map. That bump is going to blur out any reflections. Also, are you using spherical images for your reflection map? That makes a huge diff.

Do you want it to look like this?

I figured out that I need to use an HDRI image as in environment.

One thing I’m having troubles with now is reflecting other stuff. So in the attached image, I have a cone and a sphere (reflective) on a plane (that’s curved up in the very back, much like a photo studio setup). The settings I have open are for the shader of the plane the objects are on. I’d like to reflect both the cone and the sphere on the ground plane, but not reflect the HDRI. so I have it Use Environment:off. However, it still reflects the HDRI (you can see in the top right a white stripe running diagonally, that’s the plane catching the HDRI reflection. Also, only the cone is being reflected, not the sphere.

any help?

also i dont think the shadows look realistic, is that just me?

how do i pre-compute ambient occlusion?

Calculate ambient occlusion by going to render->Ambient occlusion. But first make sure your normals are all in the right direction by going to Surface Edit->Set Orientation (You want everything blue, not yellow - you’ll wind up with a dark patch if your normals are wrong).

RE the issue you’re having above - could you post your wire file?

Are your sphere and cone the exact same shader? It’s hard to tell but it almost looks like your sphere isn’t reflecting in the cone either.

It’s kind of funky but I can’t off my head figure out what the story is just by seeing that one setting.

I know that these are going to be no-brainer kind of suggestions, but it’s always good to start off with them:

check your reflection settings. Are you allowing the rays to reflect enough?

check your visibility settings (this might only be in Maya…can’t remember). Is the sphere set up to be visible in reflections?

It seems like you might have just missed something simple. It looks good so far though!

i seriously dont mean to send you to another forum, but i wrote this tutorial a while back that might help you get started with AO. im not sure how to post it any other way.

Come back here to keep the discussion going. posting a file would really help as there are several seasoned Alias gurus on this thread.

keep it up!!!

woo so i’ve gotten it to look sort of nice. i stil cant really tell the difference before and after calculating ambient occlusion (probably because my shapes are too simple… even after i added surface features to make it a bit more complex.)

any feedback on the render in general? what should i be working on to improve? or start moving on to more complex geometry?

Honestly thats a pretty nice job - at least for a test scene. Now apply those learnings to your model. :smiley:

Ambient Occlusion is really good at nailing tight diffuse shadows, like parting lines. Since you don’t really have any parting lines on those two objects you won’t get much of an effect from it.

On that subject, is there an easy way to do parting lines? I never really found a method to make them.

Honestly, not really. Just a lot of offsetting and trimming depending on your object.

I typically do all my parting lines in Pro E once I have my surfaces built, but in Alias I would offset my main surfaces (the ones that the parting lines fall on) by ~.5mm, then project my parting line on them, intersect or extend anything necessary so that I have a “loop” that forms the reveal I’m going to use as a parting line.

Then draft surfaces outward and intersect and trim.

Theres probably a lot of other ways to skin that cat as well depending on what your object is. Tube sweeps, dividing and moving your parts, etc.

You can easily exchange between Alias and Pro/E? Interesting. I’ve never really been able to open/edit Alias files in other programs. Thanks for the tips.

If you build clean and do it right - absolutely. It’s a matter of having the correct construction tolerances set and knowing what types of geometry Pro E likes, doesn’t like. This affords the ability to have a lot of parametric flexibility and utilize the things that Pro E does best (Fillets, offsets/shelling, surface swapping, etc) but still maintain the Class A surface capabilities and speed of Alias.

This is the reason that all of our products go to tooling with exterior surfaces that are straight from Alias. We own the ID through to tooling so that an engineer can never come back in, try to rebuild our design intent in Pro E and ruin it in the process.

Do you think it’s worth learning Pro/E just for Alias compatability, then? Our school only taught us Solidworks, and I picked up Alias myself. What type of file would you be putting into Pro/E? IGES? STEP?

Generally depends. IGES usually works the easiest but you can actually import native .wire files or PTC Granite (.g) files. IGES’s will auto-stitch on import which is nice because things will usually come in as solid which makes it really easy to quickly add/subtract material. For example if I’m building a speaker I could import the main body of my speaker as one object, then import a series of blocks to use as perforations from Alias and it will automatically cut out my speaker pattern. If downstream I decide I want to change my main speaker volume, I can move back in the feature tree, re-import my main body, and when I regenerate my speaker perf and other features will all stay in place. If you were to do this all in Alias you’d have to go in and manually re-intersect or trim a lot of your features.

Also works really well for things like parting lines - I can offset all my surfaces in 1 step, trim and merge and viola, instant clean parting line/reveal.

Whether or not it’s worth it - thats up to you. I’m not sure what your goals are. You may be able to do some similar behaviors in Solidworks, but since 99% of Asia uses Pro E thats what we use for manufacturing purposes.

Pro E has it’s pros and cons but learning it couldn’t hurt as it would just be another line item on your resume if you are looking for jobs.

If you know SolidWorks and Alias, you are in really good shape. Everything else out there is some combination of the two that you can work out in short time.

BTW: That test render looks good! I’m glad to see the improvement.

Part lines: Definitely easier to drop into complex models in a solid modeler (SW or Pro E). An alternative is to draw then in using PS or Illustrator. It depends on your needs.