Cycles: Volumes in the world shader behave strangle with some textures #92027

New Issue

Alaska · 2021-10-08T01:18:38+02:00

Alaska commented

2021-10-08 01:18:38 +02:00

System Information:
Operating system: Linux-5.14.0-1-amd64-x86_64-with-glibc2.32 64 Bits
Graphics card: NVIDIA GeForce RTX 3090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 470.63.01

Blender Version
Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-10-07 19:35, hash: 23791db145, and every version between master at 2.81 (That is how far I tested).
Worked: Unsure

Short description of error:
When using certain procedural textures in the volume output of the world shader in Cycles, you get unexpected results.

Exact steps for others to reproduce the error:

Create a scene in Cycles.
Change to the rendered viewport.
Open a shader editor and change to the World shader and delete the Background node.
In the World Shaderadd a Magic Texture node and connect one of the outputs to the Volume socket on the World Output node.
You will noticed that in the viewport you can see the Magic Texture is projecting light onto objects in the scene, but you can't see the Magic Texture directly.
Place a Color Ramp node between the Magic Texture and the World Output nodes. Now you can see the Magic Texture in the viewport.

Another test:

Create a scene in Cycles.
Change to the rendered viewport.
Open a shader editor and change to the World shader and delete the Background node.
Add a Noise Texture node and connect an output to the Volume socket on the World Output node.
Notice that you can see the impact the Noise Texture is having on the scene, but you can't see the Noise Texture
Place a Color Ramp between the Noise Texture and the World Output nodes. You still can't see the Nosie Texture in the scene.
Place a Volume Scatter node in the World Shader, connecting the output to the Volume socket on the World Output node and connect the output of the Color Ramp node to the Density input of the Volume Scatter node. You can now see the noise texture in the volume if you have a light in your scene.
Select the left most handle (the handle that is black) in the Color Ramp node and drag it closer to the position 0.5. You will see the results you expect until you reach the position 0.5 where the volume will seem to disappear from your scene. Yet when you look at objects in the scene, the light reaching them is still affected by a volume shader you can't see.

Here's a video demonstrating this:
Volumetrics not visibile in viewport in certain sitautions.mp4

**System Information:** Operating system: Linux-5.14.0-1-amd64-x86_64-with-glibc2.32 64 Bits Graphics card: NVIDIA GeForce RTX 3090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 470.63.01 **Blender Version** Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-10-07 19:35, hash: `23791db145`, and every version between master at 2.81 (That is how far I tested). Worked: Unsure **Short description of error:** When using certain procedural textures in the volume output of the world shader in Cycles, you get unexpected results. **Exact steps for others to reproduce the error:** 1. Create a scene in Cycles. 2. Change to the rendered viewport. 3. Open a shader editor and change to the `World` shader and delete the `Background` node. 4. In the `World Shader`add a `Magic Texture` node and connect one of the outputs to the `Volume` socket on the `World Output` node. 5. You will noticed that in the viewport you can see the `Magic Texture` is projecting light onto objects in the scene, but you can't see the `Magic Texture` directly. 6. Place a `Color Ramp` node between the `Magic Texture` and the `World Output` nodes. Now you can see the `Magic Texture` in the viewport. Another test: 1. Create a scene in Cycles. 2. Change to the rendered viewport. 3. Open a shader editor and change to the `World` shader and delete the `Background` node. 4. Add a `Noise Texture` node and connect an output to the `Volume` socket on the `World Output` node. 5. Notice that you can see the impact the `Noise Texture` is having on the scene, but you can't see the `Noise Texture` 6. Place a `Color Ramp` between the `Noise Texture` and the `World Output` nodes. You still can't see the `Nosie Texture` in the scene. 7. Place a `Volume Scatter` node in the `World Shader`, connecting the output to the `Volume` socket on the `World Output` node and connect the output of the `Color Ramp` node to the `Density` input of the `Volume Scatter` node. You can now see the noise texture in the volume if you have a light in your scene. 8. Select the left most handle (the handle that is black) in the `Color Ramp` node and drag it closer to the position `0.5`. You will see the results you expect until you reach the position `0.5` where the volume will seem to disappear from your scene. Yet when you look at objects in the scene, the light reaching them is still affected by a volume shader you can't see. Here's a video demonstrating this: [Volumetrics not visibile in viewport in certain sitautions.mp4](https://archive.blender.org/developer/F10867778/Volumetrics_not_visibile_in_viewport_in_certain_sitautions.mp4)

Alaska commented

2021-10-08 01:18:38 +02:00

Added subscriber: @Alaska

Alaska commented

2021-11-24 12:13:20 +01:00

For anyone wanting to triage this report: I just thought I would add that I have tested this again and can still reproduce it on the latest master

Pratik Borhade commented

2022-01-20 08:06:00 +01:00

Added subscriber: @PratikPB2123

Pratik Borhade commented

2022-01-20 08:06:00 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Pratik Borhade commented

2022-01-20 08:06:00 +01:00

@Alaska , Neither ColorRamp node shows texture in viewport (on current master).
In 3.0.0 it works as you said. Not tested on intermediate build (will do that later)

3.1.0	3.0.0

@Alaska , Neither ColorRamp node shows texture in viewport (on current master). In 3.0.0 it works as you said. Not tested on intermediate build (will do that later) | 3.1.0 | 3.0.0 | | -- | -- | | ![image.png](https://archive.blender.org/developer/F12812330/image.png) | ![image.png](https://archive.blender.org/developer/F12812331/image.png) |

Alaska commented

2022-01-20 09:13:54 +01:00

In #92027#1291510, @PratikPB2123 wrote:
@Alaska , Neither ColorRamp node shows texture in viewport (on current master).
In 3.0.0 it works as you said. Not tested on intermediate build (will do that later)

| 3.1.0 | 3.0.0 |
| | |

I can confirm this in the latest master.

> In #92027#1291510, @PratikPB2123 wrote: > @Alaska , Neither ColorRamp node shows texture in viewport (on current master). > In 3.0.0 it works as you said. Not tested on intermediate build (will do that later) > > | 3.1.0 | 3.0.0 | > | ![image.png](https://archive.blender.org/developer/F12812330/image.png) | ![image.png](https://archive.blender.org/developer/F12812331/image.png) | I can confirm this in the latest master.

Philipp Oeser removed the

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Cycles: Volumes in the world shader behave strangle with some textures #92027