Wrapper material issue.

[Mikele-Axiom]

hello,
Ive had some good experience with wrapper but now im stuck.
I cant figure why im still getting "screen texture projection" from my Wrapper unto to boxes. as in straight projection, making them look transparent.
i use the wrapper from vray3.6 menu and also try the vray express one, but both give the issue. https://www.youtube.com/watch?v=isRN...ture=emb_title
i also follow exactly this tutorial but still issue persists.
i play with GI affect, and with matte on secondaries options, but still an issue.
What am I missing?

attached picture and zip vray/rhino scene.
rhino v5
vray 3.6

[Zahari.Ivanov]

Hello Mikele-Axiom
I would like to share with you another forum topic, where the same issue was discussed and a solution was presented: https://forums.chaosgroup.com/forum/...-needed-please
The scene there exhibited a possible issue with how reflective materials are rendered if the background image is not very suitable for the specific workflow and I believe that the replies there could be very useful to you.

Let me know if you need any additional help or information and I will be glad to assist you.

[Mikele-Axiom]

I read the link,
i understand the workaround but it makes it very hard to get a good result. especiall with close apart reflective materials.
in this image attached i have background enviroment "off". and all thats on is the floor+wall geomatry with a genric material with texture set as 'enviroment/screen'
but still getting screnn projected texture on the cubes.
this is a bug ?
it shows it works here in minute 1:50
https://www.youtube.com/watch?v=isRN...ture=emb_title

i did this workflow with wrapper before, and it worked great. weird i cant replicate the tutorial

[Micha]

The problem is that the screen projected texture isn't "fixed" to the ground/background objects. The reflection rays don't "see" the texture like expected. For me it's a bug too.

Here an example how it should be looking: I assigned a camera mapping per Rhino tool and this mapping is right seen by the reflection rays too. It could be great if the V-Ray screen mapping could work like this.

[Mikele-Axiom]

sorry, but where do i set the "camera mapping per Rhino tool " ?
and would that work on as wrapper material (for getting transparent drop shadows... ) ?

also, in the video tutorial, shouldn't the bicycle then have the wall 'screen' projection on it like im getting with the cubes?
https://www.youtube.com/watch?v=isRN...ture=emb_title

I dont have rhino 6 to open and use the tutorial files to review the effect in them.
maybe someone can open and save as v5 with vray 3.6?
https://www.chaosgroup.com/education...rseware/assets

[Micha]

I uploaded the little tool here:
https://discourse.mcneel.com/t/wish-...231/12?u=micha
It should work with the wrapper material, since it only modify the UV coordinates of the background objects. I hope the V-Ray screen mapping problem will be solved also if we have a workaround.

At the tutorial video the issue isn't visible, since we don't see clear reflections on the bike.

[Mikele-Axiom]

this is amazing! thank you! works with wrapper too!
so i see i need to run command on each camera view change correct? meaning Batch views vray render is not possible unless i save multiple rhino files, right ?

also, im not getting the good result on projection with the floor like you got. any idea why?
scene file attached

[Micha]

Best you use a quite dense mesh. If you create the mesh from NURBS, than set all options zero, disable simple planes and set max length to a good length for your scene, maybe something like 5 cm.

Batch rendering is a problem right. Rhino supports a screen mapping to. I never tested it .... but tested now and it works, if you use a Rhino material texture. Nice, something new learned.

Just the question is, how to get Rhino material mapping and wrapper together. georgi.georgiev - do you have an idea?

[Micha]

Unfortunately I found now the Rhino screen mapping is no solution, at reflective materials the objects looks transparent too. So, a fix from the Chaosgroup is needed, so that screen mapping at reflections is using the mapped texture from the reflected objects.

[georgi.georgiev]

Hi,

As my colleague has advised this is normal and expected behavior with screen mapping.

In this particular case, the secondary bounces are affecting the materials. More specifically, the diffuse texture of the Base material in the Wrapper is being reflected. You could remedy this by adjusting the Matte for Secondary parameter to Мatte for Reflection and Refraction. This way the cubes will be reflecting the environment and since you have the Environment Overrides enabled, V-Ray will use whatever the Reflection override is set to.

In the video tutorial, you do not see this effect because the scene has a V-Ray Dome Light.