Specularity Map ???

General discussion on Thea Render for SketchUp

Moderator: Frederik

Specularity Map ???

Postby Sorceress21 » Wed Dec 30, 2015 4:14 am

Hi guys,

I'm having trouble understanding how to properly create a specularity map over a texture in Thea.

Example would be to create a hull texture for a spacecraft where some of the plating segments are more reflective than others i.e. Starfleet Aztec plating.

I have figured out how to place a spec map - assign my spec map bitmap under Material Lab/Scattering/Reflectance but that's where I have gotten lost. I cannot figure out how to now adjust the reflectance of the base diffuse material independently over the reflectance of the Spec Map.

I have tried doing this via layering the texture but then if I assign the Spec map as the diffuse bitmap the .png that is my Spec Map will not act like a true alpha channel image whereas the parts of the image that are transparent are showing the default solid black. I have only found that the alpha channel properties of the Specmap .png will only render properly if the image is assigned to the Reflectance block thus bringing me back to square one.

I hope some one here can understand what I'm trying to do and has a suggestion. I have a feeling this is something simple.
0

Sorceress21 
 

Re: Specularity Map ???

Postby Rich O Brien » Wed Dec 30, 2015 11:01 am

Your specular map goes into the Reflectance slot under the Diffuse as per this video....

0
There's a frontroom and a backroom....reverse faces
User avatar
Rich O Brien 
Administrator
 

Re: Specularity Map ???

Postby Sorceress21 » Wed Dec 30, 2015 6:05 pm

Well thank you for trying...As I said in my original post I've already done that but is that the only way as I have found no way to adjust the actual relflectance level of the spec map at all and then you can no longer adjust the relflectance level of the base diffuse layer without deleting the spec map image.

Man this was SO easy to do in Kerkythea..why they had to complicate it in Thea is beyond me.

Let me try to simplify this question:

How can you adjust the refelctivity of the base diffuse texture independently of the reflective texture AND also adjust the refelctivity level of the reflective texture itself?
0

Sorceress21 
 

Re: Specularity Map ???

Postby Rich O Brien » Wed Dec 30, 2015 6:43 pm

Sorceress21 wrote:Let me try to simplify this question:

How can you adjust the refelctivity of the base diffuse texture independently of the reflective texture AND also adjust the refelctivity level of the reflective texture itself?


Thea uses a physically correct material system. Each substrate behaves as a real world material would appear.

How reflections behaves is dependent on how you actual built your texture. The Scatter and Structure tabs control reflectivity and roughness separately.

You can also edit any bitmap by right clicking the texture button to open the Texture Lab for that bitmap.
0
There's a frontroom and a backroom....reverse faces
User avatar
Rich O Brien 
Administrator
 

Re: Specularity Map ???

Postby Sorceress21 » Wed Dec 30, 2015 8:06 pm

So how would you suggest I set this texture up to get the desired results?

Here is what I have so far:



As you can see its the effect I am after, however, I want the specular segments less reflective and the diffuse segments more reflective. I want the whole texture to be reflective, not just flat segments and fully specular segments as above.

I've tried adjusting the weight of the spec map but it has zero effect, it's either on or off regardless of what the weight is set at.

I've also tried to use layers but again, unless I place the spec map into the Reflectivity block the image will not render properly.

Is there any way I can set the texture of the spec map to render the transparent segments correctly if I set it into the Diffuse block? If that's possible then I can adjust the Value of the reflectivity of both the base diffuse layer and the spec map map to get the texture results I'm looking for. I've played with it a lot and just can't seem to figure it out.

Is this a limitation of Thea? I don't understand why the Spec Map is deleted and a flat color inserted when I adjust the value of the Reflective image, is there some setting I can change that will keep the Spec Map image and allow me to adjust its value without it replacing the image with a solid color?
0

Sorceress21 
 

Re: Specularity Map ???

Postby Pixero » Thu Dec 31, 2015 9:18 am

Here is a quick render with a checker texture on roughness.
invert the texture if you want it the other way around and play with the roughness value for amount of roughness.
roughness_checker.JPG
0
User avatar
Pixero 
 

Re: Specularity Map ???

Postby tomasz » Thu Dec 31, 2015 1:26 pm

Pixero is right. You only modify the reflection intensity at 90 degrees (perpendicular to the surface) when you put the texture into reflectance.

When using Thea you have to think about material in physical aspects. In physically based materials specular reflections are a result of a different roughness of a material surface, as in reality. When you have a polished surface, you cannot get blurred reflections/specular highlights no matter how you look at it.
0

tomasz 
SU2TH & SU2KT Developer
 

SketchUcation One-Liner Adverts

by Ad Machine » 5 minutes ago



Ad Machine 
Robot
 



 

Return to Thea

Who is online

Users browsing this forum: No registered users and 1 guest

Visit our sponsors: