Transparent Material Isssue

[werner.poetzelberger]

Hi,

 

I am expiriencing an issue with transparent (blending) materials.

 

Looking at the attached image I actually dealing with 2 different issues:

 

at 1) a polygon missbehavior occurs.

The objetcs gloves med and gloves are One 3D object using a single material on a single surface.

 

I made sure, that there are so intersecting polygons! No self intersection, no object intersecting.

 

This 'effect' does dissappear as I am separating it into into 2 objects.

 

And it gets worse if I use the 2-sided option. (in the material)

 

at 2) (and on 1 as well) there is a wrong color blending happening on parts of the objects which are transparent.

 

The transparency is controlled by a texture, which in this case is nearely to 0 at the plastic parts and some higher values at the label and the zip of the bag.

 

Its very obvious in areas wich are more opaque but also there on very transparent areas.

 

at 2) two separat objects are overlaying each other. (not touching, just one behind each other)

 

I use a Metal-workflow PBR material with a deffered alpha blending (standard blend is basicaly the same result).

 

The 'effect' stayes always the same, but differs in color ans intensity as I change values on e.g. Metalness..

 

In the second Image at 1) there I experience a wrong render - order. It is a folded transparent material (bag).
The zip disappears - is not visible through the bag in front.

This is probably an order issue which I could get around by deviding the object into different surfaces.

 

 

Werner

[silent]

Hi Werner,

 

Can we at least check the material settings? Or maybe a really small test scene with this behavior?

Thanks!

[werner.poetzelberger]

Uploaded a testscene onto Unigine FTP. Some objects have missing texture, dont worry, but the issue is visible.

(xlaevis14122015 small.zip)

 

U 2.1   Please start via the .bat file.

 

Thx.

Werner

[silent]

Hi Werner,

 

Thank you for the test scene!

 

I've managed currently to reduce artifacts (on picture #1) by using the following steps:

1. Enter in console render_deferred_transparent 1;
2. Set Transparency preset to Deferred alpha blend for plastic_transparent_clear_2 material.

I suppose, that the problem here is because the same transparent material should be rendered in different order twice (to get more realistic transparency effect). Not sure, that it is possible (according to this rendering sequence article). To solve this issue you will need to prepare your content differently: split your objects into more pieces and setup different materials for each surface with correct rendering order parameter to get more or less realistic results.

Also, I'm still waiting for our artists to check this scene to make sure that I didn't make any logical mistakes :)

 

Thanks!

[werner.poetzelberger]

Hi,

 

The setting of the render_deferred_transparent 1 helped to get rid of the render artefacts! nice.

The render order doesnt do anything good, unfortunately, even when splitting objects and materials.

So I cant see the transparent objetcs behind a transparent object.

thx

 

Right, so I read the article.

 

So, deferred is not good because of transparent behing transparent, and forward would be good, but does show artefacts and false colors.

Is that the actual outcome and summary?

 

Thx.

 

Werner

[silent]

I get slightly different results:

 

 

Anyway, we need to wait a feedback from the artists team.

[silent]

Hi Werner,
 
Quick update on your scene:

• render_deferred_transparent 1 is not required, return it to 0.
• Also, it is not required to set Deferred alpha blend state for plastic_transparent_clear_2 material.

Instead, just disable Depth Test option for all plastic materials: plastic_transparent_clear_*.
 
Also, we noticed that you are using really wrong scale in your scene. For example, on that screenshot:


white cube is only 1x1x1 unit (1x1x1 meter). We strongly recommend to use default scale in Unigine: 1 unit = 1 meter. If it is not too late, you can easily fix it by reimporting the models with correct Scale paramter in FBX Import (or modified scale in your DCC tool - Maya).

 

Thanks!

[werner.poetzelberger]

Thanks Silent.

 

Your results look like they are desired! Very good.

So I will set those parameters as you suggested.

 

Scaling to the correct size should be no problem.

 

Maybe that also helps with our physics issues.

 

Thank you very much and happy x-mas.

 

best.

Werner