View Full Version : Attempting to reflect a sky map onto a sphere

04-12-2005, 11:33 AM
I have a sphere with the following properties:

Color: 218 218 218
Luminosity: 0
Diffuse: 100
Specularity: 4
Reflection: 20
and the rest at 0

What I'm trying to do is a scene in which a chrome sphere, with white text on it, is lying in the corner of a ceiling-less room and reflecting the stormy sky above. I'm not experienced at this and I can never get my reflections to look good. I must admit I have no clue what I'm doing.

What I attempted was to make a spherical reflection map with default attributes on the sphere, but it ends up covering up the white text. The sky reflection is supposed to be subtle and muted but instead it seems like the sphere was painted that way.

To try and help matters, I turned on caustics, radiosity, high anti-aliasing, and orange-tinted(because the sky is orangy) global illumination with 30% ambiance but it still generally looks like crap.

Here's the sky map:

the sphere's texture:

I'll post the render I have so far in a few minutes when it's done. Hopefully you can give me some insight? Tips? Any advice to make it look more realistic.

04-12-2005, 12:43 PM
Here it is


As you can see, it looks pretty awful. Any tips would be appreciated.

04-12-2005, 01:13 PM
First of all use a Lightwave preset for the chrome ball as a start. You can learn a lot by tweaking those parameters. Use spot with shadow map or area light to soften your shadows. In render panel choose raytrace reflections(and also in the surface properties of the object).

Turn off radiosity until you get your surfaces right, then play with lighting your scene.

04-12-2005, 01:38 PM
Here's something else I tried. This came out a lot better...


04-12-2005, 03:21 PM

First. Make the sphere with more polygons. YOu can see the poly's on the edge.

In modeler press the n key for numeric values. Raise the segments up. OR alternatively you could nurbs the object with TAB in modeler and then in object properties raise the subdivion level up.

This will smooth out your sphere alot.

You are going for something like this right?

Area lights can give you soft shadows but you may have to scale them up a bit.

04-12-2005, 05:29 PM
that's really nice. I can't get a decent sky reflection like that. I even tried to bake a skytracer one but it didn't show up on the sphere. Also, your walls have a nice marble look. Is that just a procedural texture and some specularity?

04-12-2005, 06:12 PM
I love your your cloud map. Check out this render.

04-12-2005, 08:10 PM
The walls are low % reflective with low diffuse % and a procedural - Crumple - used sparingly.

The scene is lit by an area light sized up for soft shadows.

The sphere is 40x40 segments. It has a low diffusion % and is reflective with a little specularity and gloss. Also a nice little shader known as "fast fresnel" for the subtle edge.

The scene is set up with a background image so that the sky is in the background and is reflected in the sphere. I used no spherical mapping on the sphere. It is purely reflection.

I used textured environment. YOu can do a search for 360 degree cloud backgrounds on the web and spherical map a large sphere to surround your scene or just use the textured environment or imageworld background settings.

04-13-2005, 10:05 AM
I'm having trouble getting nice lighting with the area lights. I get very little contrast. The background looks flat and you cant tell where the walls meet the floor and each other. Any tips?

Thanks so far. I really like these renders you guys are showing me.

04-13-2005, 10:12 AM
This is a bit of a side question. Sometimes I accidentally press the E for the graph editor when I'm editing the attributes. From then on the E remains selected and I cant use the normal sliders. How do I unselect the E and go back to the way it was? I can't figure it out X(

04-13-2005, 10:34 AM
To get rid of the "E" (envelope) or "T", hold down SHIFT and click them...or was it CTRL.

One of them will work!

04-13-2005, 10:57 AM
Thanks mrunion!

Intuition, I was wondering if, in that beautiful render, you had radiosity or caustics on? And what were your settings for Fast Fresnel? What does Fast Fresnel actually do anyway?

Thanks again. You guys are really helpful.

04-13-2005, 11:11 AM
Your diffuse is waaaaayyyyyy to high. If I remember correctly, adding your diffuse and reflection should equal 100%. I would make diffuse around 20% and reflection around 80%.

Also, buy F-Prime. It will teach you a lot about surfacing and lighting due to instant feedback.

04-13-2005, 11:48 AM
I'm sorry, I didn't mention this. The 2nd render is done in f-prime. It is radiosity lit. You can get the exact same result from LW though. It just takes a little longer to render.

Use diffuse in the fresnel shader if you like subtle edge hints. Watch the reflection and diffuse settings in your scene. Too much of either on the same surfcae and it looks very 3d instead of photoreal.

Also, I like to use inverse distance in the Area light fall off to create a more diffused realistic look. If you have f-prime you don't have to guess the distance setting.

I zipped up this scene so you can look at my settings?

I just threw this together in a couple minutes so use it how you want. I've been using LW since 1995 4.0 and like to help out others when I can.

But its made in LW 8.0.1 so, if you don't have that version it may not open.

Also, I sized down the panorama image since it was too big for posting in a zip.

04-13-2005, 11:57 AM
here is the render in native LW

Reduce noise is turned on.

04-13-2005, 12:34 PM
here is the render in native LW

Reduce noise is turned on.

It looks to me like you have the Textured environment for that sky set to the wrong axis....

Try Y


04-13-2005, 01:42 PM
Hmm...how do I go about reducing the render passes to less than 17?

I've got a real nice render going that I'll post in a few...

04-13-2005, 01:57 PM
Here we are, with a redesigned wall and a new camera angle.

I really should find or make my own image map for the bricks instead of using a procedural texture but I took the low road. I still like the result :)


04-13-2005, 02:15 PM
This one is a bit better. Added a lens flare, adjusted the light so it was positioned where the bright spot in the clouds are, made the light brighter, changed it from a point to a distant, changed the ground to asphalt and added specularity to it to make it shine.


I'm very pleased :)