View Full Version : Render Question......

03-04-2004, 06:11 PM
Hello everyone.

Need some help on a project. Want to render a scene in B/W and colour for separate objects, and was hoping someone could tell me how....
In Layout you can use this thing called "Render Buffer View" (Scene - Effects - Image Processing - Add Image Filter).
I tend to use it as a filter 'cos some of the settings produce very nice renders.. especially when combined later in photoshop.
Thing is.... it works on the whole scene. Does anyone know how to do this for individual objects or individual surfaces? I'm particularly interested in the B/W Shadow/Diffuse buffer view.
I thought maybe it would work by adding it as an lscript in Surface Editor / Shaders.... but can't do it!
Sorry... there's probably no way of doing it.... but maybe someone knows another way of getting that B/W gradient look on surfaces.

Hope someone can help.

03-04-2004, 10:23 PM
Easiest way is to render seperate passes with B&W and color, then composite (utilize the alpha channels).

03-06-2004, 10:37 AM

now i'll just have to find a good tutorial for compositing. Always thought it was something for animators....
Pity there isn't more control over the rendering of individual objects and surfaces in lightwave though. I find lightwave's render engine a bit too photorealistic.......


03-06-2004, 01:42 PM
I find lightwave's render engine a bit too photorealistic.......

That's one for NewTek's marketing dept. :D

03-06-2004, 06:53 PM
:) Yeah I guess..... Would make a good advert huh?
But seriously... I think Newtek concentrate too much of their efforts on making Lightwave a perfect photo-realistic 3d anim thing.....
I think artists prefer control, rather than realism.
After all, if everyone was doing realistic 3D, than the world would be really boring. The best graphics and designs are always those that let you see things through different eyes, and in different ways.....
Not just imitating the real world.

But sure... Newtek marketing dept' can quote me if they want!! I do find it a bit too realistic!!!


03-07-2004, 03:03 AM
i don't know of a way to do it entirely in LW, but here's a relatively simple method:

in the surface editor under the 'advanced' tab, set the alpha channel to "unaffected by surface" for all of the elements that you want in black and white.

render your scene and save it as a psd (or any format that will preserve the alpha).

open it in photoshop and choose 'load selection' from the 'select' menu. choose 'alpha 1' in the dialog that comes up (should be the only option) and click ok. your color objects are now selected.

since we want to change the non-color objects, choose 'select inverse' from the 'select' menu.

open the hue/saturation dialog (image menu-->adjust-->hue/saturation) and take the saturation all the way down (-100).

voila! a mix of color with black and white.

03-07-2004, 03:22 AM
i just reread your message and i realize this may not be quite what you're after, but hopefully someone will find it useful anyway.

03-07-2004, 05:10 AM
Actually.... it was very useful. Now I know what the 'advanced' tab in Surface editor does! Never actually understood those alpha channel settings.
I wouldn't do it your way though - 'cos what I'm after is the render effect that some of the buffer views give: not quite the same as b/w in photoshop.
I will probably use your tip by using the alpha channels for the coloured surfaces, and having a second image saved with the b/w buffer view - and join em together.
I'll post a couple of images comparing normal b/w and some of the buffer views. I think it might be a slightly unused part of lightwave (along with 'render lines' in object properties), but very good one. But not now.
Now I will be glued to modeler and layout and be hitting myself for leaving things so late... again....

Thanks for the pics maxx..... i learn new things every day.

03-07-2004, 05:12 AM

by that i meant using the alpha channel as a selection in photoshop on a coloured render.... and than just copy/paste over the b/w buffer render.