Baking in reflections?

Gibbage · Apr 2010

Max2010 vray or MR

I have a cockpit, and I want to back in the raytraced reflections of the glass canopy, but im running into an issue. Its not rendering the reflections from the pilots perspective, but what is paralell too the surface. So the reflections are not rendering out correctly! Im trying to render from a camera of the pilots eye point, but its not helping.

Here is an example of the sort of reflections im trying to baked in.

In MR or Vray its just not working. Any idea's? I also want reflectivity baked into the dash and other glossy things in the cockpit.

renderhjs · Apr 2010

render it from the perspective and then use a camera map projection to render that former rendered perspective reflection back to the UV coordinates.
Reflections are always view specific so there is no other way.

Gibbage · Apr 2010

What about things like the dashboard?

00Zero · Apr 2010

you could have a black background, and render just reflections with a camera at the pilots point of view. then slap that onto your trasnparent texture.

r_fletch_r · Apr 2010

I had to do this a while back on an environment, as the lads have said camera mapping is the only way to do it. The thing is that since reflections are view dependent it tends to look like crap when the view changes. its also very prone to streaking, multiple projections can work around this but its not great. I found mentalray was prone to crashing if you tried to RTT the camera map, and had to render the screen in MR and Bake it in Scanline.

In the end we used a reflection map.

Mark Dygert · Apr 2010

How are you baking, are you using render elements > Reflection? A cube map?
What are you baking it too? The diffuse?
Are you having problems getting the reflection to look like you want or having problems capturing it?

I think Renderhjs has a good suggestion and I'd roll with it. But baking is such a blanket term its hard to say.

I can understand trying to capture the reflection of the glass but why put reflections in the dashboard its going to mostly be reflecting the canopy (which is a very weak reflection of a reflection) and the sky and normally those components are pretty matte to avoid things like blinding the pilot.

For the dashboard:
You could probably use a regular spec map and be just fine for the dashboard. You could use viewport canvas to paint a few highlights from the pers of the camera into the dashboard objects. (I suggest going with 2011 viewport canvas, much improved). But I guess if you figure it out for the canopy you might as well apply it to the dashboard, heh.

Faking the Reflection:
I'd be tempted to just render the cockpit minus the glass from the top down, with an additional z-depth pass to only get things close to the glass.
Then stretch/manipulate that set of renders using the Photoshops transform warp tool or liquefy, whatever gets the distortion the way you want.

If its going to be baked into the diffuse and never really a true refection, might as well fake it the best you can and have more control over whats displayed?

renderhjs · Apr 2010

or render a cubemap aka panorama and use that as a reflection cubemap in the engine. There should be various tutorials out there on how to setup a cubemap rendering.

Mark Dygert · Apr 2010

Like the.... polycount wiki!
http://wiki.polycount.net/Cube_Map

Gibbage · Apr 2010

Basically, the users viewpoint never changes. Its fixed in the cockpit, so baking in the reflection is optimal over an enviornment map.

Take a look at this cockpit that I did.

[ame]

http://www.youtube.com/watch?v=Ssx09oi6AcE[/ame]

You can see that you have no feeling for the glass in front of you, and also a lot of things are rather reflective in the cockpit. Also, your only viewing the cockpit from 1 fixed perspective. I was really hoping to be able to bake in reflections off of surfaces to give the cockpit more depth as its looking rather flat.

Baking in reflections?

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