I recently encountered a similar issue. When I set the material of an object to OmniGlass, I can see that the object has a transparent effect. However, when I place a light source in front of these objects, I can see a very deep shadow behind the glass, which is exactly the same as the shadow when the object is set to OmniPBR. It seems like the light is not passing through the glass. In real life, the shadow of a transparent object, such as glass, should be very faint. Could any dear friends tell me how to make the glass material allow light to pass through so that the objects behind the glass material can also be illuminated by the light?
HI @shilelieming
this part of the forum is only for vMaterials, not materials in general.
I informed a moderator to redirect your post. So you will get a better answer.
Depending on the ability of the material it is also necessary that the render engine can render physical correct behavior. If not already in use try RTX - Interactive (Path Trace) or RTX - Accurate (Iray). They support advanced rendering.
If you like. Use vMaterials and the render engines I mentioned. Have a look at the quick scene I have built.
They show the place where vMaterials can be found and that it works the way you want it to.
Hi @shilelieming ,
If you’re unable to use Iray then the next way is to click on the glass object mesh and uncheck cast shadows in the property tab, this will work for both real time and path tracer.
It all depends on your glass settings. And you really need to use either path tracing or iray. Let me dig into the settings a little and see if I can help.
Thank you very much. There are only RTX real time and RTX interactiva(Path tracing) i can chose. I wonder is my GPU device is not compatible with Iray or the RTX Accurate. Or i need to chane my GPU (RTX 5000) devices.
Oh thanks, I tried the way to uncheck the cast shadows, it certainly works. however, i also tried this way on another cube with OmniPBR material, which should not be transparent, but the shadow also disappeared. This way is a temporary solution, but i still wanna explore the true reason of i cannot make the light pass through the Omniglass.
Thank you very much. There are only RTX real time and RTX interactiva(Path tracing) i can chose. I wonder is my GPU device is not compatible with Iray or the RTX Accurate. Or i need to chane my GPU (RTX 5000) devices.
The RTX5000 is not the problem. I didn’t know that you use ISAAC SIM. I think this application does not include RTX Accurate and also vMaterials. But you can download vMaterials via the Exchange bar in the Omniverse Launcher.
This will just download the pack. The next step will be adding this to the materials bar.
Like in the picture above click the small gear wheel and Add Collection. Locate the pack of vMaterials where you downloaded it. This will add vMaterials manually to the materials bar.
You can place the pack of vMaterials to a proper path before you add them to the bar. Choose what’s best for you.
Use the RTX - Interactive. This render engine supports vMaterials well.
Yes thanks, I use Issac sim for exploring the view on a deformable transparent body . Maybe , i guess that is the weakness of using isaac sim to explore this kind of problem. I also wonder whether i can use this material in isaac sim or import this material into isaac sim. i am downloading the PORD-VMATERIAL 2 PACK software. Besides, with your information, i found in linux isaac sim 2022.2.1, there is material, it only takes 5 to 10 minutes to load the VMATERIAL, i also found Glass/Glass_Clear material and applied it onto a cube mesh. With using this material, i feel the isaac sim become a little bit slow and i spend around 5 minutes waiting for is response after i click the Glass_Clear material.
intuitively, the glass shoud be transparent, but why it is not.
@shilelieming
this glass material needs RTX - Interactive. vMaterials are built to behave like a physically correct material. The RTX Real-Time Engine can’t handle this to pretend its nature to be real-time.
It would be best if you use RTX - Interactive. The error will be gone and the material will no longer be red. A red material shows that something is wrong like a red error message.
That is cool. I make this glass cube transparent and i also can see the object behind the glass cube, that is really good.
what i will do for the next step is to add a deformable physical material to this glass cube and make it deformable, and add a sticker on one of its 6 surfaces of this glass cube. Is this feasible? what i wanna do is to simulate a scene in this picture, where a sticker is attached to a soft transparent cube. My plan is divided into 3 steps, 1) make the cube transparent in simulation 2) add the sticker using Texture on one surface of this glass cube, or just add a thin cube attached to one surface of the glass cube, i don’t know which method is better. 3) make the glass cube deformable and apply some contact force on it and make it deformable, then observe the sticker and monitor how the sticker deforms in Python script. That is a huge project, and i found few tutorials of the isaac sim Texture, can you recommend some helpful tutorials of the Texture using? I really appreciate your favor.
Ah… you are using Issac Sim. This is the issue for sure. Issac Sim, whilst built on the same RTX platform, is not nearly as powerful for actual rendering as USD Composer. Issac Sim is amazing for simulation of the physical world and robotics, but for more advanced rendering features you are much better off downloading USD Composer.
what i need to do is only collect data from the simulation to support my algorithm, so the rendering can be not very accurate, however, it also cannot be counterintuitive. Thanks very much for your help.
where can I get some helpful tutorials about the texture usage? I wanna give the glass cube a customized texture.
Here is a good place to start
https://docs.omniverse.nvidia.com/materials-and-rendering/latest/index.html
The realistic shadows through glass can be better acheived by turning “fast refraction shadows” on the mesh itself and using Path Tracing to render.
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