PDA

View Full Version : Skydome with Final Gather??


lestaylor
04-28-2012, 09:07 PM
I am in the process of creating a skydome in Maya and I am using final gather with a light blue environment background color. My sky .tif file is pretty much the same light blue color with some white clouds. I also have an additional directional light to further mimic the sun light.

Here is the issue. The referenced models render a darker shade with the skydome. If I take the skydome out, it renders correctly.

Is there a way to make sure the skydome does not block the final gather, or am I going to have to render the skydome out separately and compose it in Adobe Premiere/After Effects?

Note: I am trying to eliminate Maya Sun and Sky and IBL lighting as options for lighting this scene. I want to recreate daytime light with a directional light, skydome, and final gathering.

Thank you for any suggestions on this...

Bitter
04-29-2012, 09:10 PM
When you say "skydome" do you mean an object in your scene with a texture on it?

lestaylor
04-30-2012, 12:40 AM
Yes. I have a half of a sphere surrounding my scene. The sphere has a surface shader applied to it with a file mapped into its out color.

Bitter
04-30-2012, 12:45 AM
Don't do that. :p

It not only casts shadows as geometry, it also messes with your raytrace acceleration structure by becoming part of your geometry/intersection testing. It slows down rendering.

Is your tif floating point? (high dynamic range) If it's not, then it won't provide much lighting information and will be sort of muddy.

www.hdrlabs.com has a decent free online library.

lestaylor
04-30-2012, 04:47 PM
So..You are saying I should do away with the "skydome" method? How would you create the sky? IBL?

Bitter
04-30-2012, 04:53 PM
Definitely an IBL or camera environment instead. (The Maya IBL is just a fancy UI for a camera environment.)

lestaylor
04-30-2012, 06:20 PM
When you refer to camera environment, are you referring to background plates(image planes) and projection? For example: http://www.qvolabs.com/maya_camera_projection_basic.html

Obviously, I am new to environment creation and thank you for your advice.

Bitter
04-30-2012, 09:07 PM
Those are backplates.

I mean like the mib_lookup_spherical or the Maya IBL created in the render globals.

Using an HDR attached to the camera environment slot under the mental ray rollout, you can apply the mib_lookup_spherical and render with that.

lestaylor
05-01-2012, 01:23 AM
Wow. I used Maya IBL. Major difference... Im rendering out a 1080hd frame with final gathering (250), global illum (500), 4k layered textures on ref'd files, and raytaced shadows in about a minute. Looks so much better.

I need mores processing power (only 8 cores now) or need to figure out how to cut the render down in other ways... Thanks again!

CGTalk Moderation
05-01-2012, 01:23 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.