question about Material UV settings

[dcauldwell_cg]

Re: question about Material UV settings

Minimar
I spent hours yesterday carrying out an almost identical experiment and I also tried various standard visopt settings - with the same negative results. It is really frustrating!
Bump works, displacement doesn't.

Damien
As you seem to be one of the few people to have displacement working, is there any chance of you posting a working example with its settings. At least that way we have a starting point.

Thanks

David

[dalomar_cg]

Re: question about Material UV settings

Well, the issue at the heart of this whole discussion is material UVs. Basically without them, doing anything other than a material of a solid color is very hard. So even if what your doing has nothing to do with colors, but still needs to reference UV information, then a linked material is really the best way to go. So when I did my displacement experiment, I created a linked material from a bogus SU material (of course it didn't really matter what the material was), put a simple gray diffuse layer over the linked layer (for simplicities sake and to see the displaced effect better), and was able to use a map for displacement. When I originally added the displacement, the rendered result with displacement was nearly indistinguishable from the one with out, except for right at the edges. So I increased the actual depth of the displacement by increasing the texture multiplier (in my case this went from 1 to 10). This may be the issue that all of you might be having, that the actual distance of the displacement is not showing up in the rendered result. The actual distance of the displacement depends on 3 things; scene units, displacement amount (in the displacement rollout of v-ray options), and the texture multiplier of the the displaced texture (or procedural map). By default the displacement amount is set to one and the texture multiplier is 1, so that will lead to a displacement that is equal to one scene unit. If you change your scene units then you effectively change the amount of displacement. If your scene units are very small, like inches or millimeters, then the default displacement value may not be noticeable for an object like a large wall.

[dcauldwell_cg]

Re: question about Material UV settings

Damien

Boy, this is hard work! OK, here we go. Here is just one screenshot showing the settings and the outcome from the experiments.

-regular texture from sketchup (which works with a the bump map)
-overlayed with a plain vray texture
-scene units 1mm
-displacement map is the same as the on ethat works as a bump map
-displacement 'amount' - tried 1 - 10000
-texture multiplier - tried 1 - 10000

results zilch!!

What next?

[kwistenbiebel1]

Re: question about Material UV settings

The 'overlaying' with an extra vraymaterial on top of the linked material is kind of tedius don't you think? Seems like one step too many to obtain something that could be a lot simpler if the linking of SU materials would be somehow revised and made more powerful (= automated, preserving Sketchup uv-mapping on textures in added layers, ability to import vismats while preserving the assigned SU uv-mappings, etc....

In 99% of the cases for making a material , my workflow would involve linking a Sketchup material as this is the only way to have the Sketchup textures positioned and scaled just as I would want them.

You guys have the most powerful render engine on the market.
The 'carbon copy' porting of Vray from 3dsMax to Sketchup is successfull resulting in a very solid software package.

I think now it's time to focus on optimising the workflow towards faster use in Sketchup.
The sole reason I personnaly didn't buy Vray for Sketchup yet is because I would loose too much time in the material setup phase. I will definitely jump on the train when things would be improved in that area....

[dalomar_cg]

Re: question about Material UV settings

@David
I think there might be one overlooked issue. In your displacement settings, you have your edge length set to 1 px which may be at the root of the issue. Basically have that set to 1 is that the edge of one displaced triangle can't be longer than one pixel which is very, very small. Subsequently because of that (and SU's tendency to have very few original triangles) there may not actually be enough subdivisions to recreate the displaced mesh (eventhough 512 is a lot of subdivisions). You can try setting your Edge length to something like 6 or something, and that might take care of it.

Also, try disabling relative to BBox. I tried finding more information on it, but nothing really out there. Its off by default, so that would be my recommendation. After those two things I'm absolutely stumped.


@Biebel
I completely understand what your saying. Unfortunately we are at the mercy of SketchUp on this one because of how the program as a whole does things. We need to find some way to get around this and allow material creation to be a much more streamlined process. Its hard because this is possibly one of the most heavily tied components to SketchUp so our processes have to work hand in hand with SketchUp, and right now its not working as well as it should. Workflow, UI, and optimization are on our list of issues to work on, so we're in the process of finding a better solution.

[joe_b]

Re: question about Material UV settings

@Biebel
I completely understand what your saying. Unfortunately we are at the mercy of SketchUp on this one because of how the program as a whole does things.

We can't really blame Sketchup - it does what it does. Basically we didn't realize the UV hiccup ( how uvs are only generated if a texture is on them ) until we were a bit late in the game. We'll have to come up with a solution because at the moment any part of our material process that relies on mapping is very drawn-out and complicated.

I am going to see if I can get something in to alleviate some of the strain during the current service release I'm working on. I just need to make it so these uvs are always generated regardless. As well as probably implementing biebel's suggestion regarding automatic linking to Sketchup materials).

As always - we're open to new suggestions on how to help you with your workflow

[kwistenbiebel1]

Re: question about Material UV settings

Hey thanks Dalomar and Joeb!
That's great news.
I am sure you guys will figure a way to do the trick as the rest of the software allready is very solid.

Thanks for hearing your customers and 'nearly' cutomers

Regards,
Biebel

[dalomar_cg]

Re: question about Material UV settings

I am sure you guys will figure a way

You guys = Joe...I'm just here to explain to him all of the super complicated things (like meshing something)..he's the brain child who codes it all. ;D (this is a big inside joke)

[joe_b]

Re: question about Material UV settings

You guys = Joe...I'm just here to explain to him all of the super complicated things (like meshing something)..he's the brain child who codes it all. ;D (this is a big inside joke)

I don't know the command to mesh something in Rhino and suddenly I'm a stupid person right?

[kwistenbiebel1]

Re: question about Material UV settings

Clearly the issue on how to do uv-mapping is not answered.

I would say the most logical thing would be doing texture positioning in SU.
Vray should pick up this uv-mapping automatically in the Vray material editor.
The current vraylinked material doesn't handle this properly, since it doesn't allow extra adding of maps (i.e transparancy maps , etc...).
Most of the time the extra bitmaps you want to add (bump, clip, gloss maps, specular maps,displecement etc...)have the same image size as the diffuse texture.
So one would expect(because the size is the same) it will be uv-mapped the same as the diffuse texture.

Is this something that will be revised?In most other render engines it works this way, so I can't imagine it could not be done in Vray.


thanks for listening,
biebel

[dalomar_cg]

Re: question about Material UV settings

V-Ray does grab this mapping info. The mapping info is used for any other maps (bump, displacement, reflection, glossiness...). The only map it can't do that with is the transparency map, because that must be done through the SketchUp material settings (all of the settings of the linked diffuse layer are grabbed from the SU material and cannot be overridden in the v-ray material editor).

[kwistenbiebel1]

Re: question about Material UV settings

If the transparency bitmap has the same image size as the diffuse one....why can't it jus follow the same rules as the others (bump, refl. map, etc...) ?

[dalomar_cg]

Re: question about Material UV settings

I was under the assumption that SU allowed for transparency maps in its materials, which it doesn't, so that basically leads the transparency map "unmappable" for a linked material (in this case assume just makes an ass of me :-[). I talked to Joe about this and we think we may just allow the transparency map (not the color) to be changed from within the linked layer. In the mean time, I posted a work around for setting the transparency map with UV info from a linked material on your other thread (the one in the bug section). If desired I can post it over here.