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Hi has anyone else had this problem : sometimes when I render a scene it is just black and it's quick to render but it's just black and it says that its done , and the next time I have used the same scene , characters , ect and there is no problem and it turns out fine , it's like a hit and miss . does anyone know what the problem would be ?
Answer from ChatGTP -
If an **Iray render in DAZ Studio is completely black**, the most common causes are:### 1. No Lights in the Scene
Unlike the default viewport, Iray requires actual light sources.
Check for:
* An HDRI environment map
* Distant lights
* Spotlights
* Emissive surfacesGo to:
**Render Settings → Environment**Make sure:
* **Environment Mode** is set to **Dome and Scene** or **Dome Only**
* An HDRI is loaded if you're relying on environment lighting---
### 2. Camera Inside an Object
If the camera is inside a wall, prop, or character, Iray may render black.
Try:
* Switching to another camera
* Moving the camera back
* Looking through the **Perspective View** first---
### 3. Environment Intensity Too Low
In **Render Settings → Environment**:
* Increase **Environment Intensity** to 1–5
* Check **Environment Map** is not missing---
### 4. Tone Mapping Exposure Problem
Go to:
**Render Settings → Tone Mapping**
Check:
* **EV (Exposure Value)** around 13–15
* If EV is too high (20+), the scene may appear nearly blackQuick test:
* Set **EV = 13**
* Render again---
### 5. GPU Memory Failure
If Iray runs out of VRAM, rendering can fail or produce unexpected results.
Check the log:
**Help → Troubleshooting → View Log File**
Look for:
* "CUDA memory allocation failed"
* "Out of memory"If so:
* Hide unnecessary objects
* Reduce texture sizes
* Render with CPU enabled---
### 6. Corrupt Render Settings
Try:
**Render Settings → Editor → Preset → NVIDIA Iray**
Reload the default Iray settings.
---
### 7. Rendering Through a Hidden Camera
Verify:
* The camera being rendered is the correct one.
* The camera isn't disabled or inside geometry.---
### 8. Emissive Objects Not Producing Light
If using emissive materials:
* Increase **Luminance**
* Check **Emission Temperature**
* Make sure the emissive surface is visible to the renderer---
### Fast Diagnostic Test
Create a new scene:
1. Add a primitive cube.
2. Add a camera.
3. Create a spotlight.
4. Render with Iray.If that renders correctly, the issue is specific to your original scene (lighting, camera, or render settings).
Can you tell me:
* Your DAZ Studio version?
* Whether the viewport is visible but the final render is black?
* Are you using an HDRI, lights, or only emissive materials?That will help narrow down the exact cause.
Sounds like you were out of vram. Everytime you hit render, daz uses a little bit more of Vram unti the program restarts I think. So the first time you render a scene there would be no problem, but subconsequence renders might have some issue.
Also usually when daz is out of Vram it would push the render to CPU, did you turn off CPU rendering?I'd agree with Pharrell, I've seen this on my end quite often. If you turn on the CPU fallback it should run but it'll take a lot more time.
You should look into optimizing the scene first, try lowering the subdivision if you've increased it and/or using scripts like "scene optimizer". There's quite a few of those optimizing programs, I don't recall which was the best but these are worth looking into...
(https://www.daz3d.com/scene-optimizer)
(https://www.daz3d.com/camera-cutaway)
(https://www.daz3d.com/camera-view-optimizer)I have a 4070 ti with 12 GB VRAM, 64 GB system RAM and hit this quite often. FYI, you need 4x the system RAM to be able to use the full amount of VRAM due to the way daz prepares the scene for render.
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