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Beeno1974
03-29-2011, 04:46 AM
Hi all,

I'm entirely new to LW and am trying to find out how to apply multiple surfaces to a polygon. As example, I have a box which has a node surface. I want to project a logo onto one side of the box, however, this logo would be a node surface of which the alpha is controlled by a texture image (or just some other procedural).

How exactly do I make the whole box Surface 1 and apply Surface 2 onto some polygons on top of Surface 1 (So Surface 1 still shines through in the transparent areas).

Thanks.
Beeno

Dexter2999
03-29-2011, 01:01 PM
You should really start out over here
http://www.newtek.com/lightwave/24hours_training.php

Scroll down almost halfway down the page is the Surfacing section.
William "Proton" Vaughn has made many videos that are very helpful and free.

Good Luck

Tobian
03-29-2011, 01:45 PM
Beeno, what you basically need to use is an alpha channel. You can either have the alpha be part of the texture, or just be another file (make sure it's saved in a lossless format, such as PNG or TGA etc, NOT JPEG). The Alpha chanel then functions as it does in traditional 2D software... You can use the alpha to drive the 'material mixer' if you want 2 different surfaces completely. Or you can just use the alpha channel to mix up differing surfacing properties, which can do more or less the same thing.

here's a couple of simple examples of how to mix things together, using an embedded alpha...

JonW
03-29-2011, 03:48 PM
You should really start out over here
http://www.newtek.com/lightwave/24hours_training.php

Scroll down almost halfway down the page is the Surfacing section.
William "Proton" Vaughn has made many videos that are very helpful and free.

Good Luck

Even if you don't think a particular tutorial is for your needs, look at as many as you can. At some later stage you will ask "now where did I see that!". LW is a about continual learning & virtually all of us have only scratched the surface! Set yourself some projects (not too difficult at first) as though they are real jobs & follow there through to the end, but make sure you make lots of mistakes!

Trial & error with a lot or error!

Beeno1974
03-29-2011, 05:13 PM
Thanks Tobian,

So how would I go about mapping an image over 2 surfaces. Let's say I'm making a computer mouse. The top cover has a shiny strip running down the middle. So basically matte on the sides yet shiny down the middle. That's easy enough by applying separate surfaces to the polygons. But now I want to project a logo that spans these surfaces. Do I need to go into both surfaces and add the texture separately and setup the projection for each?

I'm trying to comprehend this process. Comparing to how one would do it in something like Modo where you would start by applying one surface to the whole object, then overlay the shiny piece on those polygons and lastly a 3rd material which draws the logo on top of all of this using Alpha. Seems to me one needs to approach surfacing in LW differently?

Tobian
03-29-2011, 05:44 PM
A surface can span multiple bits of model and or layers, even objects, if you are careful :) Surfaces are just a set of properties applied to a set of polygons.

Unfortunately LW does not have a shader tree like Modo, so you can't layer things like a logo across multiple surfaces like that. You can however have the same image be duplicated to as many surfaces as you like. you could just copy and paste the surface, ontop of another surface and then change the values for that one.

It has to be said though you can do quite sophisticated layering techniques within a single surface, using alpha masks or weight maps. In nodes a weight map can function just like an alpha mask, so you can create differing surface properties (such as matte-ness or glossiness and alter them using the mask.

Beeno1974
03-29-2011, 07:10 PM
Ok, I agree that being able to compose within the node editor is cool and flexible. I've tried your idea of using a weight map with the material mixer (Unfortunately it means modeler won't show the mixed texture). This is what I get. The output seems to be blending the map between 0% and 100% on the edge faces, instead of giving a crisp cut. I've tried turning off the smoothing option but obviously that just made all the faces flat.

First image shows my weight map and second a render. How would I make the edges crisp? From my weight map screenshot it looks like the map would not be blending the edges but perhaps the subdivision surface causes this?

Tobian
03-29-2011, 08:16 PM
Well 2 things...

1) When making a weight map, make sure you select all the points and set them to zero before painting on your weight map, otherwise you'll get crisp blending weirdness like that and the erroneous display in the OGL viewport. Lasso all the other points and under the map>general>set map value and type in a value of 0 for them, which should correct the OGL display and the gradient.

2) To get sharp edges for your weight map, simply modify the weight map with a gradient. Feed the weightmap node into the gradient input and the gradient output into the alpha mixer. You can then modify the gradient to your tastes, including setting the keys to have the 'stepped' type, to get ultra crisp transitions.

Beeno1974
03-29-2011, 10:00 PM
Thanks that did work out. In case anyone reads this in future I've attached a simple example I came up with. The object has one surface attached to it with 2 weight maps. The red area is controlled with weightmap 1 and the yellow bubbles material with weightmap 2. The Stereo text mixed in a 3rd material which had transparency. As Tobian said you would need Gradients to specify how sharp the transition between them is.

I find positioning the text projection was unnecessarily difficult without any way to interactively move it in the viewport.

Tobian
03-30-2011, 04:07 AM
Nice it worked out for you. That's not necessarily the best or most efficient way to do all of that by the way :) The node system is very flexible, but yes the lack of a visual feedback is somewhat annoying: That said, you could preview it using VPR in layout. (ur using Fprime, if you have that.)

In terms of rendering efficiency, you're better off just manipulating the channels, than mixing actual materials, unless you are trying to create sophisticated effects like a gloss coat.