Having problems with glass shadow in DS 4.5
Kattey
Posts: 2,899
Hello.
I'm experimenting with various glass settings trying to create a believable scene where light is shining through a glass bauble. My problem is that no matter what I tried there is no pretty colored shadow from the glass like on forth picture here, with ruby wine glass. My shadows so far just blobs of uniform grey with no indication that they are thrown by a glass, colored or otherwise. Can anybody help me please?
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Comments
The Opacity needs to be set to the complementary colour of the transmitted light - so for red wine you would want to apply a map that was cyan (green and blue) to block those colours and let the red through. Because opacity is a single slider in the default shader you do need to use a map - a shader made in Shader Mixer will have a colour picker, so you can just pick the colour you want (and could be set up to invert the colour, I suppose, which would simplify the process).
Thanks, Richard! Is it possible to add that node to a existing shader? And if yes, how? Any instructions around?
Oh, and I got a shader from Wonderous Wares which includes a opacity color option (with map) for a glass shader but when I change the color of opacity it changes the color of the glass, and shadow remains the same grey thing. Even if I color the image map file with cyan (for a red bottle) shadows remains grey and only glass itself changes for even more red.
If you want to apply coloured transparency to an existing shader you have to do it with a map - if you are wanting a uniform affect over an entire material just apply a solid texture (or a Layered Image Editor texture with a single solid-colour layer) to the slider - it shows as a numerical slider, butt hat's cosmetic (it was felt to be more user friendly) and gets translated to a colour when it's passed to the renderer, so map colours will also go through to the renderer..
Not sure about the Wondrous Wares problem - and i can't recall if I have the product.
I'm saying that WW shader already have opacity color and map channel (not only strength) but it seems to affect only the glass opacity, not the glass shadow opacity anyway.
P.S. My lights are white with raytracing and Raytrace Depth is about 5
Try setting up Refraction for both the glass and liqiud...search Google for a list of Index of Refraction. From memory I think water is 1.33 and glass starting around 1.52 and upward depending on the glass.
Refraction is on, I've checked -_-
Ok, using a layer of uniform color in opacity channel I managed to make a colored shadow but it is still a blob (colored now), nothing like a real-life glass shadow. What should I do next? Should I make a real opacity map in addition to using color? Or use caustics?
To save us quessing can you post a screenshot of the render, your surfaces and render settings please otherwise we are flying blind. Also exactly what lights you are using as there is more to getting realistic results than surfaces. lighting plays a big part to.
Ok, there are two renders, first one without colored opacity, second one with blue colored opacity (done via L.I.E.). The light is a single spotlight with raytracing, the flat surface has no reflection and no ambiance strength. Shader mode is glossy (metallic).
I don't need ultra-realisting results for the setup that simple but I would like the glass shadow to behave better.
Sorry about this Kattey but I am struggling to understand what issue you are having...it all looks fine to me with one spot light used....The only thing that might need adjusting is Shadow Bias in the spotlight settings...I would guess it is set to 1 where 0.1 might give a better result apart from that I do see the problem.
Render settings look ok
You said Refraction is set up properly with the correct IOR and Strength.
The render of the wine does not appear to be shadow....if you take a close look at the image, you'll see both the shadow, which is grayish, and the nice sparkly red caustics...
I don't have WW but if is capable of producing caustics, then there should be a camera preset with it.
Yes, I've checked -_- IOS is 1.52 and Strength is 100%
Um, camera preset? I don't understand what camera has to do with it. Can I add caustics to an existing shader?
Um, camera preset? I don't understand what camera has to do with it. Can I add caustics to an existing shader?
3Delight, and DS, by default don't have the cameras set to do caustics. So you need to use a camera with caustics enabled.
Bryce and Carrara, if I recall, will do them by default.
Here's a simple camera...
http://forumarchive.daz3d.com/postimages/origimage_1_1843041.jpg
Also, the WW set uses Uber ights...which will do caustics, the default DS lights won't...(or didn't last time I checked). So a standard spot, even with that camera, won't be enough to pull it off. But any 'shader' light, will...Uberlights qualify there.
To get caustics, as far as I am aware, you need special lights, surface settings, and camera all created with Shader Mixer. There is a sample scene in the Shader Mixer content folders, but I'm not sure if it's currently working (it was broken at one point).
Technically true...but it's not the only way, just the easiest. You can build custom, from scratch shaders that turn on the needed features, too. But, I believe that the UberSurface has the 'surface' part on...basically the surface needs to be made visible to photons, in addition to rays. I'm not 100% sure of that, because it's been a while since I did anything with it
Also any 'shader' light should be casting photons, too...or should be able to. If not then, a simple light with that needs to be made, too.
The camera is the key item as the standard camera doesn't have the code to read photons, so no matter how they get there, it won't be able to do anything with them.
Bryce and Carrara will do caustics a lot easier than DS...so will the Reality plugin (Lux)...heck, even the standalone 3Delight does them easier than DS.
Is this what you are after?
Crude but I didn't want to spend much time if it wasn't what you wanted.
mjc1016, thank you very much, I'll try it!
Szark, yes, more or less, I can work from here on, I guess :) Which settings did you use?
check shader mixter tutorial of daz 3d you tube video ^^
http://www.youtube.com/watch?v=FwCHxSTlOQo&list=PL5606C0A5A62058AB
http://www.youtube.com/watch?v=G2lwC6HHTrU&list=PL5606C0A5A62058AB
(you may find more about shader mixer , but these two video
seems same what you hope I think)
(Actually,, this week ,, I am struglling with shader mixer ,and now trying each tutorial ^^;)
but still,,chaostic camera,, and shader light,, these setting are difficult for me to adjust,,
sometimes it work,, sometimes I miss something,, so I can not full use shader mixer still,,
but these tutorial must help you I beleve.
Before I go and take screenshots of all the settings I would like to check something. Your screenshot of the surfaces I can't tell if the liqiud is a separate mesh as this will only work if it is. My example above is just that two separate meshes and I only applied what Richard suggested to the liguid mesh only and with one difference I added a med red to the refraction channel of the liguid.
This was just a quick test render through DAZStudio using the Reality Plugin. One meshlight, the glass model set to glass, the liquid material of the same model set to water. As mentioned this was just a test, but if left to render it would have cleared up the fireflies and noise, produce the realistic caustic effects. You might want to consider it as another option.
Thanks, FirstBastion. I suspected that Reality is capable to do that and I have that plugin but I don't really want to use it. It does look very nice though, better than in Bryce :)
Szark, the mesh for the glass has a separate water mesh but I made it invisible, as I was focused on glass itself, reasoning that effect from empty glass I desire is quite similar to water effect anyway. But the object does have a separate mesh water.
kitakoredaz, thank you very much, I wasn't aware of those videos
From my side I don't seem to be able to take an existing shader from the scene and add a node to it. Something messes up and even if I apply same shader back to scene without changing anything, it seems to lack half of things.
Nope...nothing wrong....it's a 'feature'...
SM collapses/hides unused/unchanged values. Basically make sure there's something in each 'slot' you want to keep visible.
I am so sorry about this but my only computer that can run any form of Daz Studio just went poof. I didn't write any settings down or taken any screenshots proir.
I meant to test everything in the latest beta before answering, but I haven't had the time. :-S I think the Refraction caustics are broken (either that or I just don't know how to get them to work). I posted an explanation on how to get at least refraction to work here. Pasting the relevant parts here too:
You can use the My Library/Scenes/Shader Mixer/Caustic Sample scene as a base for reflection caustics. You need to select the DAZ logo (shuriken looking thingy) surface then in Shader Mixer select File-> Import From Scene… and click Accept on the window that appears (i.e. “Material”). You then need to connect the output of Ray Type Test(8) brick to the only free input connector on the If Else(7) brick and the latter output to Reflection Colour on the DAZ Default Material (2) brick. Once you have fixed it, save it as a brick network (File->Save Shader…) and use that instead of the Caustics Sample. You can also save a Shader preset; for this to work you need to apply the shader to a surface first, though.
Thanks, ReDave, I'll try it!
I'm trying to follow the tutorial on Advanced lightning above, and in second part the tutorial doesn't give me any caustics from "Example scene caustic shader" although it worked for an example built from ground zero. I wonder if anybody encountered same thing.
The glass shader doesn't seem to give caustics even in the latest version of Studio.
I feel so too,,yeah I tested many times,,
sometimes it work,, but I try again,, same step. it can not work.(about caustic effect)
I can not find which is wrong. but I know 3delight say "dzcausticmap can not be found"
whenever I lender with caustic camera. (either success or not,,)
I made caustic material shader about vase with shader mixture
and set "glass" type,, it sometimes work. but not about reflaction.
or just exchange surface of vase shader to chrome it made so strong caustic effect.
then after that exchange shader to glass shader with change caustic type chrome to glass,
only seems to work about reflection. no or so tiny reflaction effect I think.
I tried with ds 4.5.1.56 all test.