- HELP with HDRI -

[jsruk]

This is the problem: when i put some HDRI for my scene lightning and when i turn off all scene lights (spots, area etc.), i don't have specularity on my objects and some materials just can't look realistic. First image shows my render, but on second i need specular on selected area, how too do that? Or how to fake that specularity

[shakesoda]

those are REFLECTIONS your talking about, it looks like crap because your scene is empty. also lower your reflections and add fresnel, it will look a lot better, and for the specularity you need either lights or a new HDRI.

[jsruk]

I know what is reflection and what is specularity, but what if i have in my HDRI sun, then i'm not gonna have specular from that sun, right?

[dppd69]

jsruck, you know that the specularity is the reflection of the light source.
So your HDRI can "generate" specularity ONLY if the light source (the sun or whatever you want) IS visible in the HDRI image.
The usual tricks are:
1) add the light source in your HDRI with an external tool (search on Google, I saw a tutorial about that)
2) to use a spotlight with only Affect Specularity enabled and the shadows disabled.

Hope it helps
Cheers Dario

[shakesoda]

Originally Posted by jsruk

I know what is reflection and what is specularity, but what if i have in my HDRI sun, then i'm not gonna have specular from that sun, right?

right, for specularity you need lights. It doesn't matter if the sun is in it or not, you can't get specularity from HDRI's.

Originally Posted by dppd69

jsruck, you know that the specularity is the reflection of the light source.
So your HDRI can "generate" specularity ONLY if the light source (the sun or whatever you want) IS visible in the HDRI image.

HDRI's can't "generate" specularity in LW, only lights can.

[The IC]

in real life a specular and a reflection are the exact same thing, the parts you circled wouldnt have a bright "specular" reflection because its just sky reflecting off those areas

speculars in 3d are just a cheap way of trying to make something look reflective when its not, and they actually make things look unrealistic

[dppd69]

Originally Posted by shakesoda

HDRI's can't "generate" specularity in LW, only lights can.

Obviously I meant "reflect". In 3D, you have to use the specularity parameter because 3d lights are fake lights and they cannot reflect.
HDRI is a "real world picture" used to illuminate the scene, its a sort of real world light simulation. So if a HDRI contains a visible lightsource, you can see it reflecting on a car as part of the whole HDRI reflection. That's it.

>shakesoda
no offence, btw, just to make my thinking clear to jsruk.

Cheers, Dario

[The IC]

dppd69 makes a good point, lights in most 3d programs dont actually make anything for an object to reflect, which is kinda silly

[NightEye]

Originally Posted by The IC

in real life a specular and a reflection are the exact same thing, the parts you circled wouldnt have a bright "specular" reflection because its just sky reflecting off those areas

speculars in 3d are just a cheap way of trying to make something look reflective when its not, and they actually make things look unrealistic

Exactly.. There was a topic about speculars on LWG somewhere, with a link to a tutorial explaining just that

EDIT:
http://www.savinoff.com/home/?chapte...tion=beginners That one.

[bfx]

Just saw this.

One trick to use ....

Model some lights.

A simple flat poly will work.

Set diffuse to zero and lum to 100% or more. Color to whatever it should be for any particular light.

Turn off all shadow options and disable being affected by any lights.

Position them where the 'lights' in your hdri would be and then they'll be reflected.

I usually attach any lights in the scene to the appropriate 'light' poly.

If you're using interpolated the polys will contibute to the oveall lighting but the overall falloff is pretty steep.

Bumping lum way up - 1500 % up to whatever - may help but near items get really washed out.

bfx