surface attributes: values & image maps

[Dick Ma]

What is the relationships in Surface Editor between the values of surface attributes & image maps?

for examples, specularity is 20% and also enable texture using a greyscale image?

what about the effects of Luminosity, Diffuse, Reflection or what so ever? anyone try to make a test?

also, what is the effect of using a full-color RGB image instead of greyscale image on those surface attributes?

[JulianW]

Hi,

it should all be in the manual, but off the top of my head,


if you apply a texture map to an attribute the texture map ignores the base value of the attribute, unless the texture has an alpha value of less than 100% (where the value shows through to some extent)
if you use an RGB image it effectively converts the image to grayscale before using the texture.

hope that helps,


JW.

[Dick Ma]

Is that mean 100% white in texture map means 0% in value and
100% black means 100% in value?

[Mylenium]

Hi Julian,

Sorry, but I have to correct you on that. In certain channels LW will not override the base values with the ones from the textures if they are not 0 or 100%. It will create some sort of inbetween blended value instead which makes it difficult to predict results. Combine that with using different modes on multiple texture layers and off you are into the land of confusion.

Mylenium

[JulianW]

Ahh reply in haste, repent at leisure. yup you are right some of what I said was completely wrong.

this is how it works (no it really is this time)

It's easiest to imagine textures as a stack of transparent sheets (like Cels in animation) each with something on them. The base value would be the paper underneath all of the sheets. The result is that anywhere that you have partially or fully transparent bits in your layers of texture the base value will show through.

This is easier to understand when you realise that the procedural textures that come with lightwave only take one Colour/Value as parameters and then adjust the Alpha value of the layer accordingly. It's like each Cel is painted with varying amounts of one colour of paint letting the other layers show through underneath where the paint is thin or not there.

Image Maps are just like solid layers (unless they have an Alpha channel built in), and Gradients are solid unless you choose to set the alpha values on the control points to less than 100% when some of the layers underneath will show through.

Of course things get more complicated when you change the layers Blending Mode from normal, but that's the basics.

Sorry for confusing things with my first answer,


JW.