1
$\begingroup$

I have two textures ready to apply on a mesh of a space ship. One is the texture of the hull of the space ship itself, the other is the lighting coming from the ship's windows as well as other light sources on the ship.

I need to have the first texture emit no light and be affected by external light sources, while the second emits light. Is there a way that I can have these two textures with these two different behaviors in the Cycles Render engine? I've posted examples of the two textures below.

Regular Texture Light Texture

$\endgroup$
  • $\begingroup$ Dont know if this is what your asking. But you can try this, blender.stackexchange.com/questions/77071/… Just select the faces you want to have the light and apply emission shader to it. $\endgroup$ – icYou520 Aug 28 '17 at 21:39
  • $\begingroup$ I gave that a try, and got the top of the ship to go bright white, completely obscuring the textures altogether, which might be a step in the right direction. If it helps, I posted screenshots of the textures in question above, so it might be more obvious what I mean. The one that's mostly black needs to be emitting light, whereas the other one needs to be affected by that light source and others. $\endgroup$ – Aaron Aug 28 '17 at 21:50
1
$\begingroup$

You can use the following steps :

  • create two UV maps in the vertex panel

uv maps

  • create a material for all faces of the hull like this :

hull material

A diffuse BSDF (for the hull details) and a Emission BSDF (for the windows ligght) are added together (using a Mix BSDF should be better). The strength of the emission BSDF is increased to 10. The diffuse BSDF is connected with the hull details image which is connected to the UV map of the hull. The Emission BSDF is connected with the windows light image which is connected to the UV map of the window.

  • Unwrap the hull on the hull image like this (note that windows are painted with black)

hull details UV map

  • Unwrap the windows on a white part of the windows light image. Then unwrap all other faces on a black part (they are all stacked in the orange square at the bottom)

windows light unwrap

The size of the windows light can be very small (256px x 256px) because it contains only white and black surfaces.

Here is a final render :

final render

If you add an object near the window, you will see that it will be lighted by the window light.

windows light effect on an object

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.