Some strange glass effects

  • Hi,


    I tested the glass material in different environments. It looks like glass can be tinted per diffuse color if there is a skybox or horizon preset used. Rhino transparency color doesn't work.


    If I set a dark environment per sun system and use a spot light, than the glass tint is gone.


    Also I tried to get an air balloon look, I tried to make a plastic light transparent, but over 4% transparency I got a black material, if a spot light is used only. Per GI light it works better, but it looks like the transparency is without tint, the color tint is by the diffuse surface only.


    Two other points - keyword "frosted" shows no effect and the light shadow of the semi transparent material is missing.


    -Micha


    PS: Looks like I post enough for several days of reading, testing, fixing for the next weeks.

  • Hi Micha


    thanks for your in-depth testing ;)


    The described behaviour is known and by design in order to make order independent transparency rendering real-time capable. Here's some "behind the scenes" info for better understanding what's going on:

    - Semi-transparent objects are only affected by atmosphere lighting (with approximated atmosphere occlusion) & direct sunlight (the spotlight therefore has no effect)

    - Shadow casting of semi-transparent objects is not supported (also performance/feasibility reasons)

    - Surfaces with transparent materials can not be light emitters at the same time (this is a rendering hack, which makes no sense in real-world, just put the light emitter behind)


    Hope that helps for a better understanding :)

  • Thank you for the insights. Maybe we see some improvements on this area if multiple GPU support allow more calculation power.

    - Surfaces with transparent materials can not be light emitters at the same time (this is a rendering hack, which makes no sense in real-world, just put the light emitter behind)

    That's really hard. Maybe we can talk about it. ;)


    From Octane render I like an emitter based workflow and often I used a transparency map to get soft light edges or special light shapes. From an users view it is a must. Could you not find a solution? Maybe a transparency for visibility to camera and in reflections at least? Attached a simple screenshot for what it would be needed.

  • Good that we're talking about, because that use case on the screenshot is actually a non-issue. ;) As long as you only use the transparency for masking everything should work as expected - just set transparency to 0%, select your transparency mask texture and set a emissive color.


    In general regarding certain shortcomings due to optimization: Please bear in mind Enscape is designed to cope with huge architectural projects with potentially thousands of light sources, millions of polygons & a large amount of transparent windows. In order to provide real-time performance for such projects we usually have to compromise on some lighting computations and usually prefer to offer a very close & plausible approximation instead of aiming for 100% accurate results that would require hours of rendering time ;)

  • Thank you for point me in the right direction, the emissive material works, it was outside from the camera view and I expected a lighting effect, but room stays dark. So, we come to an other problem - see two attached images, only the view is a little bit zoomed. I hope this can be fixed, because it would cause that I couldn't use Enscape.


    I understand the need of the RT optimizations, but for example this scene is very light. Also, it could be a great feature to choose between time optimization and full scene support. So, it would be great if Enscape could be used as quick single shot renderer or as super fast RT viewer.

    For example an interior: Enscape render times are approx. 10s at one single GPU. This is extreme faster than 20 min at a Dual Xeon with 32 threads. I think, Enscape lost a lot of users in the space between this both worlds. If we could get a high end interior rendering per two GPU within one minute, than this would change the render world. I could render interior animations I never thought about it because the long render times. A switch to disable some of the optimizations would help a lot, not all scene are heavy architecture models.


    Options to disable optimization could be easy to understand like:

    * keep objects in reflection

    * keep unseen objects (needed for emitters)

    * ...

  • Additional to my last post I have two questions: why frosted doesn't work and why is there a bump effect per default?


    For example I have seen the strange bump effect on the car glass at this render:

    Office building Render

    That is no bump effect. Bump/Normal mapping means the manipulation of the surface normal for shading only. What you see there is refraction as is happens for mediums denser than air, you can observe it on real objects like a water bottle.

  • Here a real project example - I try to get a tinted glass rack, but it doesn't work. I suppose so it can't cost to much render power to support a tinting.


    (It's also an example where my client will say - please less reflection at the glass rack, it's to much distracting.)


    Please, try to fix both. Enscape rendering looks so great and nice, only I don't get what my clients need.

  • Here a real project example - I try to get a tinted glass rack, but it doesn't work. I suppose so it can't cost to much render power to support a tinting.


    (It's also an example where my client will say - please less reflection at the glass rack, it's to much distracting.)


    Please, try to fix both. Enscape rendering looks so great and nice, only I don't get what my clients need.

    We'll probably revise how we interpret the given parameters by Rhino until the official release and are confident that you'll definitely be able to achieve the required effect in Enscape. Like in Revit you should then be able to define a tint color for transparent surfaces & also be able to reduce the glossiness & reflectivity as you wish.

  • - Surfaces with transparent materials can not be light emitters at the same time (this is a rendering hack, which makes no sense in real-world, just put the light emitter behind)

    I'm working on a project and found, there is to much automatic in the code and it's difficult to work around.


    For example I can't set a fire texture that is transparent, emit light and isn't affected by lighting.


    An other usage for emissive transparency - 3D people set to emissive allow get a abstract flat look from every view. At my current project I would like to place many of this people but set them to 50% transparency. Not possible at Enscape, no artistic freedom to mix the material slider like wanted. :(

    (Attached an example that show the nice flat look of 3D people. A transparency is missed.)


    So, not anything makes sense in the real-world, but is useful at viz work. Please keep the artistic freedom.

  • Like in Revit you should then be able to define a tint color for transparent surfaces & also be able to reduce the glossiness & reflectivity as you wish.


    We have the greatest problems to make glazing that is clear but non-reflective at the same time (in Revit). Is there an example somewhere (or tips) on how to achieve this?

  • We have the greatest problems to make glazing that is clear but non-reflective at the same time (in Revit). Is there an example somewhere (or tips) on how to achieve this?

    You can reduce the reflectance for glazing materials to reduce the amount of reflections. If you want to have no reflections at all you'll need to setup a generic material with low glossiness & reflectivity values. Hope that helps.