Metal and light?

[medeamajic]

When I use the preset metal materials like gold or brass to design a logo just dangling in space it never shows up. If I use a plastic preset shader it will be lit up. If I select a light grey back ground the gold object will be visible. Maybe the laws of lighting are being used in Carrara but I am surprized that with out choosing a light grey back ground that the gold object does not light but the blue plastic object will.

Does anyone know why the gold metal does not light as bright as plastic when objects danlge in space? I use spot light, distant light and the light bulb presets but they do me no good with metal materials unless I use a light grey back ground. With a white background the gold is to birght.

[bwtr]

As I read it with a lot of stuff in 3D, things have to have an enviorenment in which to work. If you check out, I think the metals which have low Reflectivity with low Shinyness, have less problems in your instance maybe.

[jbshorty]

Med, reflective objects must have something to reflect. It's as simple as that...

[Grendel]

shorty is 100% correct, if you want it to look good drop an HDRI in it or softboxes and then put a backdrop in separate.

[medeamajic]

Thanks everyone for your feedback. I think I will just use the light grey background.

[jones2000u]

hope this might help as well: if your metal is flat, it won't reflect much - or too much of what you don't want. So this is assuming the metal is flat on at the camera:

insert an image plane with an ordinary parametric image on it, like a blurred scene/landscape/roomscene or something. Put the plane behind the camera, so the camera is in FRONT of the plane and pointing at your object. The image on the plane should reflect back into your metal object.

Now if you point a spotlight directly at the plane from somewhere in front of the camera you can control the strength of it.

That way you can use a white background (or black) because the light is reflecting back from your metal object.

[julvr]

Or... use your image as a background, and select a solid backdrop.

[three3dguy]

How the heck do you make a HDR image? Can photoshop do this?

[three3dguy]

I found a post on another board that answer this question....

I realized that some people are creating HDRI's from pre-existing stock photo's, making multiple versions with different levels/contrasts and then re-compositing as an HDRI file.

This does not make an HDRI! It defeats the purpose.
The purpose of an HDRI is to have a complete and detailed spectrum of color and light information for EVERY detail in an image.
This creates a realistic light spectrum in 3D applications and gives hyper realistic details to photography.

To do this you NEED to take mutlibracketed photo's of the same scene from under exposed to over exposed and a few steps in between.
Without this method HDRI files will not have a full range of light and color information.
So essentially, you CAN NOT make a true HDRI from a stock photo unless you have multiple exposure brackets of that same photo.

[jones2000u]

Hi threeDdguy

Looks like you answered your own question! Just to expand that quote, you can't make one out of a single stock image because it cannot possibly have the full range of light/colour/detail information that you would get if you did a proper full bracket photographically.

Have a look in Flickr - there are some really interesting images where a lot of people create HDR images in PS just for the effects they get from the technique. Some are weird, some are really nice!

[three3dguy]

Thanks jones2000u!,..





Got another question how do I go about aligning up the plane or planes hdr image reflections against both sides of a car body and not reflecting off the walls . The car sit in the middle between two (building bricks) walls and the rear part of the car is facing right smack infront of the camera lens (about 10-? feet away). The camera will be panning somewhat and you be able to see both side of the car and rear section.