HDRI visible on flat/Transparency objects, Plz help

# 1 06-11-2012 , 02:11 PM

Registered User
Join Date: May 2008

Posts: 245

HDRI visible on flat/Transparency objects, Plz help

I have scene with HDRI environment, but I have issue with the visibility of HDRI on the glass and flat objects
Its very reflected(looks like mirror). its also visible on some part of the body as you see in the image.

any advice Here please.

regards

Attached Thumbnails

Click image for larger version

Name: TRK-HDRI.jpg
Views: 336
Size: 112.2 KB
ID: 52839

Quote

# 2 06-11-2012 , 02:49 PM

Registered User
Join Date: Mar 2007

Posts: 1,055

I think this is just normal reflection, or am I mistaken?

Quote

# 3 06-11-2012 , 05:38 PM

Super Moderator
Join Date: Dec 2006

Location: South FL

Posts: 3,522

Yeah that looks pretty normal. Maybe some material tweaks are in order. Is that image tonemapped?

- Genny
__________________
::|| My CG Blog ||::
::|| My Maya FAQ ||::

Quote

# 4 06-11-2012 , 06:53 PM

Registered User
Join Date: May 2008

Posts: 245

Hi guys Thanks for reply

I made a polygon sphere and I applied a surfaceshader material with HDRI . The sphere has been Uv mapped.

front Truck window's glass (material Phong and with reflection of 0.500), If I tweak the reflection ( drop it to 0.300) its looks ok but than Its loses the quality of glass.

I notice Any flat surface or objects with reflection materials, where its faces direct to the HDRI, its gets full/direct reflection of HDRI ( that is the issue).

maybe you have more experience with that sort of issue.

please say something if you know something.

regards

Last edited by dubai3d; 06-11-2012 at 07:13 PM.

Quote

# 5 06-11-2012 , 07:35 PM

Super Moderator
Join Date: Dec 2006

Location: South FL

Posts: 3,522

That's what I thought, material tweaks are needed. Standard Maya materials aren't suited for glass right out the box because the reflectivity is pretty constant regardless of the viewing angle, extra nodes are needed to simulate Fresnel reflections (like sampler info node), or you could use the mia_material_x, it behaves more realistically and even has a Fresnel reflections checkbox. Is there any reflection blurring on the phong/blinns? If not, then I can see why the reflections look crisp and strange.

- Genny
__________________
::|| My CG Blog ||::
::|| My Maya FAQ ||::

Quote

# 6 06-11-2012 , 08:13 PM

Registered User
Join Date: May 2008

Posts: 245

you Right GenT,

The Maya materials are not really good for glass. Here after bit of tweaking the reflection I got this newest update Image, but still doesn't looks like glass. I need bit more work on it.

Mia materials are good as you suggest, I'll Try with Mia materials. I know you are good in info sample connections,

Gen if there is any sources( link, tutorials....etc.) related to this subject please forward or mention, so I can follow the links.

thanks again

Quote

# 7 06-11-2012 , 11:25 PM

Super Moderator
Join Date: Dec 2006

Location: South FL

Posts: 3,522

Actually the mia_material has presets for glass, you could try one of those. If you have to use the Maya shaders then you could apply this method to their reflectivity channel.

- Genny
__________________
::|| My CG Blog ||::
::|| My Maya FAQ ||::

Quote

# 8 07-11-2012 , 04:13 AM

Registered User
Join Date: Feb 2011

Posts: 17

Actually the mia_material has presets for glass, you could try one of those. If you have to use the Maya shaders then you could apply this method to their reflectivity channel.

Originally Posted by GecT

Thanks for your share! Is it your blog?
How many methods to make glass in maya?
i'm a very beginner and i think there are some below ways:
1. use mia_material and preset to glass
2. use mia_material and use fresnel reflection checkbox
3. use dielectric_material
4. use blinn material and increase transparency value and decrease reflection.
please share some advice
Thanks!

Quote

# 9 07-11-2012 , 06:44 AM

Super Moderator
Join Date: Dec 2006

Location: South FL

Posts: 3,522

Yep that's my blog.

I'd say 1 and 2 are the same deal, the glass presets use Fresnel reflections.

Using the samplerInfo node and a ramp(linked above) to control the blinn's reflectivity is another way but I don't see much point in it if you're using Mental Ray, the mia_material_x is more realistic and extremely versatile. I'd rather avoid the hassle.

- Genny
__________________
::|| My CG Blog ||::
::|| My Maya FAQ ||::

Quote

# 10 07-11-2012 , 08:23 AM

Registered User
Join Date: May 2008

Posts: 245

Hi guys,

Yeah you right gen. maya mia-Materials has good preset glass (thin, thick, frozen....) so I used Mia_Materials with preset glass thin.

I'm getting bit tired of changing so many materials, so i can not see my error any more. maybe you can help me out.
this is the last render, what do you think Guy's? looks like a glass?

regards

Attached Thumbnails

Click image for larger version

Name: TRK_NEW01.jpeg
Views: 325
Size: 157.0 KB
ID: 52847

Quote

# 11 07-11-2012 , 08:26 AM

Registered User
Join Date: May 2008

Posts: 245

I may need more reflection on the glass, but the mia_material_x1 reflection is on highest (1.0).

Quote

# 12 07-11-2012 , 08:48 AM

Registered User
Join Date: Feb 2011

Posts: 17

It's look good to me. If you need more reflection on the glass i think adjust BRDF can solver this issue

Quote

# 13 07-11-2012 , 09:34 AM

Registered User
Join Date: May 2008

Posts: 245

@duyquyen

Good Point, I'll try this option.

regards

Quote

# 14 07-11-2012 , 11:34 AM

Registered User
Join Date: May 2008

Posts: 245

its already on. there is no much think I can change, I tweak little bit of BRDF but seem nothing changed.

here is the render, that is what I can get so far. but it looks ok, much better than before.

Attached Thumbnails