various bugs/questions

[nizu]

Hi,
VB25 is working pretty well at this point, so each time i encountered a problem in last 2 months it was easy to work around it and go on
But finally I've put together a list of bugs / missing features / requests, i post here instead of github to check if these are really missing/bug and to see which of these interest other people too.

I suppose Andrey already knows these well and has his roadmap for them , for me -as env/game artist these are some of the most interesting questions :

-- vray light select render element :
It's one of the coolest feature of v2.0 , outputs a render channel with the contribution of selected light.
It should be part of color channels plugin , but i can't figure out the .vrscene syntax (..the id number for the channel , how to specify the lamp ..)

--material/texture clamping options :
I think Vray has a "clamp" option for every kind texture plugin (or almost) that cuts all values above 1. it would be useful as a checkbox on all textures.
Alternatively .. it would also work to have a "clamp diffuse" and "clamp reflections" in the material panel to clamp the whole material texture stack (in practice it's only important for diff. and ref. )
(Btw.. in case 1 , it would be fine to have clamp affect all channels of a texture ..to avoid cluttering the ui .. it's not as important as the invert checkbox , which i appreciate that is independent per each channel )

Example of where i'd use this : Using advanced blend modes (like ADD ) it's possible to have as result a channel with intensity above 1.
This is normal for bump or displace etc.. but can be bad for diffuse and reflection color if you don't mean to make the material emissive (often i just want to brighten the diffuse or reflections using another map but making sure it doesn't exceed 1.0 )

--Layered material opacities bug ?
It seems that whenever i reduce the opacity of a BRDF (parameter "weight" , to blend it with the one below) all brdfs become transparent ... could this be a bug ? that the weight change applies to all instead of only the current one ?

--Multiple UV channels
UI buttons are there but i can't get it to work , whether it's for using 2 image textures using different uv channels (in same object and material ) or for baking textures (using 1 uv channel ) to another channel.
Is it supposed to be working ?
Btw ..I remember experimenting with the script in 2.49 ..and it was a pain because of vray using 3dsMax conventions (channels are numbered not named , and the concept of "active channel" doesn't exist .. sigh , i hope it won't be too crazy to find a solution )

vertex weight paint to texture
Weight paint groups converted to a gradient texture (black to white and /or opaque to transp. ) could be used as control maps for all sorts of effects. (using it as stencil mostly)
Typical use would be blending rocks and grass textures on a ground mesh , with the bonus of painting vertex group being done per object without needing a bitmap .. in such cases would be a lot easier than using bitmaps.
I have no idea how hard is to implement this ..exporting the mesh data with vertex weight (or is it already there for hair ?)
Similar to weight paint is vertex color paint to color the objects directly ..nice but, imho less important than weight paint.

[bdancer]

Re: various bugs/questions

>>vray light select render element
I think its not yet ported to Standalone.

>>material/texture clamping options :
I don't get it. Some examples in 3ds max vray?
Also check Common panel for some mult params.

>>Layered material opacities bug ?
Send me a test scene.

>>Multiple UV channels
You have to reexport meshes after changing texture UV settings.

>>vertex weight paint to texture
May be possible with TexMeshVertexColor.

[nizu]

Re: various bugs/questions

Thanks for the reply , It's quite a list of subjects.. i know it requires more infos , i'll keep testing and report whenever i find out more, by now :

>>>>vray light select render element
>>I think its not yet ported to Standalone.

I see in Chaosgroup page it's in Vray Maya 2.0 .. doesn't that mean it's in standalone too ?
Using plgparams is hard to tell because "light select" it's not a plugin by itself .. could still be inside "RenderChannelColor" ..but the alias number and the syntax can only be seen from a sample maya vrscene..

>>>>material/texture clamping options :
>>I don't get it. Some examples in 3ds max vray? Also check Common panel for some mult params.

In 3dsMax it's a checkbox in the 'output' panel present in all textures (the panel with curves and brightness control) . So it's a max feature , but supported by Vray.

But i checked some standalone plugins now .. it's not in all of them (like layered or bitmap..) So it requires to pass the textures through a "TexClamp" ?.. Ouch
Oh well .. it would work also adding a "clamp" vray texture, to use 'manually' only when needed (to clamp the previous textures in the stack , or clamp a texture by name , whichever is easier to implement)

Back in Max i always checked that when using "VrayComp" or anytime i mixed a few textures, it's to make sure your material doesn't become emissive (diffuse pixels with value >1.0) or has reflections >1.0 even if you used "add" , multiply >1 or the mult. params you mentioned like "color mult" > 1.0
It's just a minor feature, but it allows to do complex blending while remaining sure the material is physically correct. (by cutting all values above the usual 1.0 limit )


>>>>Layered material opacities bug ?
>>Send me a test scene.
>>>>Multiple UV channels
>>You have to reexport meshes after changing texture UV settings.

I'll test and post more. !

>>>>vertex weight paint to texture
>>May be possible with TexMeshVertexColor.

That should be the plugin, It says "vertex color" and i don't see a TexPlugin for "vertex weight" .. but i guess it's the same : the source can be Blender vertex color (RGB) or weight (float ..so grayscale) .
Checking "plgparams" output the plugin seems to require to write the color for all vertexes in a list ..but i can't understand more. Anyway , would be nice if it's feasible.

EDIT : Ah..Wait, problems : TexMeshVertexColor is not exactly it : if i understand that means 1 texture would work only for 1 object (listing vertex colors in the texture ..)

But This thing is only useful if you can apply the same material to various objects and have each object use his own vertex colors otherwise it has little or no advantage over a texture..
"TexMeshVertexColorChannel" .. sounds more like it : you only specify a vertex weightgroup (or vertex color channel ) ...of course all objects with that material must have one with that name.

Big problem is ... i can't see any mention of vertexcolor channels in the geometry mesh plugin ... no idea how to export those with the mesh data..

[nizu]

Re: various bugs/questions

..continuing with the 2 questions i skipped in last post:

Test blend file download : http://dl.dropbox.com/u/3068741/laye...ke%20uvs.blend
Contains 2 scenes : layered mat. and Bake

Layered material opacity

Scene contains a material : 1°diffuse brdf layer , 2° glossy brdf layer.

I expected the "weight" of the glossy layer (2°) to make only that layer transparent , showing the diffuse red below.
Instead i get all the material transparent (..it shouldn't affect 1° layer )

Multi UV and bake:
i tested again , on a simple scene multiple uvs do work, but i found some issues :

-- if i use more than 1 uv channel , all textures must point explicitly to their channel.
In Blender internal , you specify uv for the textures using channel 2 , but you can leave the other's uv textbox empty. (empty UV Layer text box = B.I. will use the default channel )
With VB25 , if you leave any text box empty seems all textures will use default uv ?

--another issue with VB confusing layers numbers :
when using 3 layers , of which 1st is just for bake , I made a test scene with an object :

UV 1 for bake , a planar unwrap (not used by any texture)
UV 2 a stretched and skewed projection
UV 3 planar projection rotated 45°

It renders incorrectly:
-- it bakes to channel 1 ok.
-- it writes all 3 channels in geometry file ok.
-- the color textures should use channel 2 and 3 , instead i read in textures.vrscene they use channels 1 and 2.

-- the bake will always be done on layer 1
In Blender Internal you use the 'selected layer' highlight and 'render to' icon (in uv channel list) to control default uv and bake to UV. (Works well but honestly not very intuitive..)
VB will always bake to channel 1 .
I'm not sure what's the most user-friendly solution : either match B.I. behaviour exactly or add a textbox to VB bake rollout to select "bake to" layer ..

[bdancer]

Re: various bugs/questions

>>Layered material opacity
Layered mats are a little tricky =)
First, they are done not like a blender stack - in blender bottom is top and here top is top - so glossy should be in top of diffuse.
Second thing - weight is smth like layer cut-out mask (and btw may be even doesn't work will check this). To make a reflection just use Reflection slider in shader settings.
Sorry nizy really busy now to fix such complex things...

[nizu]

Re: various bugs/questions

Hi,

I see : bottom-up order ! then using the reflection slider it works.

That's great, so i can do what i meant initially, bypass something i find weird about Vray : the fact that vraymaterial has no independent hilight intensity control .. (only hilight glossiness )
I know it's how Vray works , not a problem in VB , But sometimes it's useful to decrease specs indipendently from raytrace reflections..

No hurry with all the rest .. i made quite a messy list of stuff , whenever you need a test scene or clarification about my issue just post.
I should have time in next weeks to look better at the questions myself , i'll post more details.

[agorodesign]

Re: various bugs/questions

Hi guys,
I think I've found a closely related bug in the multi-layer UV mapping: To use the second (or third, fourth, etc) UV channel, the object must also have a texture using the first UV channel.

I've uploaded a simple test case: www.agorodesign.com/temp/uv_error.zip

On the cube, the 1st texture uses the 1st uv channel ("square")
The 2nd texture uses the 2nd uv channel ("angled")

To replicate the problem:
Disable the 1st texture, and the angled texture still shows up fine. Delete the 1st texture and the 2nd texture reverts to using the 1st layer uv mapping, even though the 2nd layer is specified.

Thanks!

[voytov]

Re: various bugs/questions

And a one more "family member" I described below, in this case the material nodes are the subject:
viewtopic.php?f=8&t=569&p=3469&sid=9e5f519a4ad7d84 9d8c0922216f2b7d8#p3462
The thing is, if you mix two nodes with a texture, it will always use default UVLayer, even if you assign a different UV to that texture in any possible slots/checkboxes etc..

...I'm not 100% if this is a bug, as mixing texture in material nodes may be not linked to ANY real material/geometry, so it may be not able to derive info in which UV set it is nested and should use..

[nizu]

Re: various bugs/questions

AgoroDesign : the bug you say seems to be the same of my test scene ,
The mesh export is fine , all channels in right order.
But in texture export yes , if channel 1 is unused it's skipped and 2 is wrongly listed as 1..
Also i think order can be wrong .. if my material has 3 maps using uvs in order 2,3,1 ..in the export they're listed as 1,2,3..

I blame 3dsMAx (and what Vray got from it) .. it makes sense that translating Blender uv names into simple numbers is a bit messy.
If i remember correctly my experiments with vb 2.49 , Probably the conversion to numbers should be made on a list of all uvs of the scene , not by single object or material.

That would fix also the problem (that was in 2.49 too) when you had 1 material applied to 2+ objects all of them had to have same number of uv channels and in same order , or VB would get confused.
(so i guess the name-number list should be done considering the whole scene ) EDIT : or considering all objets using a material ..yes i blame 3dsmax..

Voytov : i haven't tried VB nodes yet , all i can say it's always complicate when passing a map through another (in B.I. nodes or in VB normal stack) which properties (tiling,uv,..) are inherited and which aren't .. i was confused and had problems in BI nodes too.

[voytov]

Re: various bugs/questions

I'd like to emphasize that apart from that specific issue/behaviour texturing in VB material nodes works very well/stable - and gives great effects, for now this is my favourite way of composing materials..

[agorodesign]

Re: various bugs/questions

Nizu:

You're right- in re-reading your 3rd post, it is the same bug indeed. It's odd and erroneous behaviour, but at least it has an easy workaround- just assign a texture with no influence to use that 1st uv channel.

I definitely tore my hair out figuring that out though!

[nizu]

Re: various bugs/questions

Hi,
Yes , that seems to work : placing a dummy texture in the material .
In general, to ensure the conversion name -> number is done correctly all uv channel names existing in the scene must be used at lest once in a material.

i think what messes up the list is uv_channels that aren't used in any material , but exist on some object.

I said yesterday that conversion should be done on the whole scene to have correct conversion/dictionary ... i checked the code and That's already so , but :

If i understand the python code ,The question i think is : dictionary is done from a list of uvs used by all materials , but it should be done listing uvs from objects
to ensure unused channels still get their id and don't mess up the rest.

Regarding the "default channel" and the problems when UV textboxes are left empty ..i don't think it can be fixed :
Vray doesn't have the concept of object's 'default channel' altogheter , so there's no way to 'tag' a channel per each object and no easy way to tell Vray textures to use a different channel on a per object basis.
(could be done , but a huge effort for a minor issue)
I suppose we'll always have to follow the rule of " whenever using multiple uv channels in a material , fill all uv textboxes "


And there's a catch here ... the current system fails in some complex situations , but also avoids some confusion related to vray missing default uvs .
If the list was built from objects and not from materials .. there could be errors like missing textures when they have empty uv textbox (default uv)
Current system wrongly assigns a lot of textures to id=1 .. But that ensures simple materials always work..

Ok .. i'll leave Andrey think and decide a solution , but from all this , i realize here it would make sense adapt VB to Vray a little more (instead of trying to make it work exactly like Blender)

In the end , What if VB worked like this: in object panel we could manually assign a channel number to each channel name (default =1) allowing more than 1 name to use same number, and in textures we could use the numbers only ?
I know it sounds exagerate , and annoying for the user .. but seems the only 'complete' fix for me atm.

Edit : to clarify , when i say "annoying" i only mean the switch would take some effort , but after that it would work just as well as Blender's way.
I do think Blender's way (names) is better than numbers .. but not by much and in the end , since Vray works with numbers .. VB would be more reliable and intuitive using numbers too
(i now believe a "under the hood" translation would never work 100% , because of the missing concept of "default channel" )

Actually i think not Just VB but also BF Blender should have some support for UV channels numbers (in addtion to names).. they're used by FBX and OBJ export and it's currently a pain to export multi-uv meshes to any game engine..
(that is .. names are a slightly better solution , but numbers are very popular and common..)

[voytov]

Re: various bugs/questions

Just wanted to note that Andrey added "numeric" names to the script recently. Now if you use integers instead of names they will not be converted to strings. Tested and really works!

[voytov]

Re: various bugs/questions

Hi Andrey,
I collected a bunch of issues and possible bugs that came into my eyes recently..

There is a scene showing some of them: http://www.eurorender.com/nodes_test_20120208.zip (1,2,3,6)

1. For glass materials: If fog colour (HSV) V>0 then CPU RT mode will not start correctly (black screen, rendering finishes after some 0.28 sec)
2. Mixing refractives in material nodes: the second refractive material will not be ever mixed, no matter what is the mixing factor
3. If non-displaced material is mixed (through nodes) with displaced one, the dispalcement will also appear on the area where there was 100% non-displaced material mapped
4. In VRaySky Map the option "take settings from the sun" is not active. It will now always take settings from sun, even when unchecked.
5. When "CIE overcast" mode is set the glow on the sky is always in the centre of image - not at the sun's position. Is that normal?
6. In "Influence" section of VRaySky Map, when Environment/Background is checked it also covers GI, Reflections and Refractions in effect. Is it possible to separate these to have only background and no influence from vraysky on GI, Reflections, Refractions?

Best regards
W

(It's on latest V-Ray 2.2; V2B build 43742 with script updated)

[bdancer]

Re: various bugs/questions

3. Displace is always applied to the whole object. Nothing to do with that right now. Its how it works in vray.
6. Just create some dummy texture and assign it to the overrides.

Everything else will be checked.