Transparency doesn't work with Raycast Node in EEVEE #67
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Reference: Triager-bot/blender-bug-reports#67
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Original bug report: https://projects.blender.org/blender/blender/issues/157257
System Information
Operating system: Windows-11-10.0.22631-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2070 SUPER NVIDIA Corporation NVIDIA 591.86 Vulkan Backend
Blender Version
Broken: version: 5.1.0, branch: blender-v5.1-release, commit date: 2026-03-16 18:50, hash:
adfe2921d5f3Worked: (newest version of Blender that worked as expected)
Short description of error
Alpha / Transparency doesn't work when using the output of an Raycast Node as a mask in EEVEE. In Cycles everything works fine.
Exact steps for others to reproduce the error
Checkout the attached blendfile:
raycast_doesnt_work_with_transparency_in_eevee.blend
In the shader the Raycast node gives a usable mask, which works in cycles.
But in EEVEE the whole Mesh disappears. I would consider this a bug, or is it from a technical perspective just not possible to use raycast and transparency together in EEVEE?
Report is clear
LLM Reasoning
Got it, let's see. The question is whether the bug report clearly describes the issue. First, check the clarity of the text and steps to reproduce.
The title says "Transparency doesn't work with Raycast Node in EEVEE". The body has a short description: Alpha/transparency doesn't work when using Raycast output as mask in EEVEE (works in Cycles). Then exact steps: checkout the blendfile, mention the video. So the steps are there (even if it's an attached file, but the user provided that). The issue is clearly stated—transparency with Raycast in EEVEE not working, works in Cycles. So yes, it's clear.
JSON Data
{
"llm_judgement": true,
"processing_time": 8.873135
}
Report is specific
LLM Reasoning
Got it, let's analyze this bug report. The title is "Transparency doesn't work with Raycast Node in EEVEE". The body mentions that alpha/transparency fails when using Raycast node output as a mask in EEVEE (but works in Cycles). The steps include checking an attached blendfile and video.
First, the key here is whether it's specific or generic. Specific issues are about a particular feature interaction (like Raycast Node + Transparency in EEVEE), while generic would be vague like "crashing during rendering". This report is about a specific combination: Raycast Node and transparency in EEVEE, with exact steps to reproduce (using the blendfile). So it's a specific issue.
JSON Data
{
"llm_judgement": true,
"processing_time": 9.730887
}
Report flagged as NOT a duplicate by LLM
Eevee issue with transparency
https://projects.blender.org/blender/blender/issues/156149
System Information
Operating system: Windows-11-10.0.26100-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2080 Ti NVIDIA Corporation NVIDIA 591.74 Vulkan Backend
Blender Version
Broken: version: 5.1.0, branch: blender-v5.1-release, commit date: 2026-03-16 18:50, hash:
adfe2921d5f3Worked: (newest version of Blender that worked as expected)
Short description of error
The leaves dont show the correct transparency when plugged into a mix shader node, emission and transparency and the alpha of the texture in the factor socket. it worked fine till 5.0.1
Steps to reproduce the issue:
emission node
transparency node
plugged into a mix shader node
plug into the factor a texture with transparency
[Based on the default startup or an attached .blend file (as simple as possible)]
LLM Reasoning
Got it, let's analyze these two bug reports. First, look at the descriptions and steps.
Bug report 1 is about Raycast Node output not working with transparency in EEVEE—alpha/transparency doesn't work when using Raycast as a mask. Steps involve checking a blendfile where Raycast works in Cycles but not EEVEE, causing mesh to disappear.
Bug report 2 is about leaves' transparency not showing correctly when plugged into a mix shader (emission + transparency) with texture alpha in factor. The issue started after 5.0.1.
The key here: Report 1's problem is specific to Raycast Node and EEVEE transparency, while Report 2 is about general transparency in a mix shader with texture alpha. Different scenarios—Raycast vs. mix shader with texture. So they're not the same issue. Therefore, answer is No.
JSON Data
{
"llm_judgement": false,
"processing_time": 13.281981,
"duplicate_report_number": "156149"
}
Report flagged as NOT a duplicate by LLM
Render Pipeline Raytraced Transparency does not seem to work.
https://projects.blender.org/blender/blender/issues/26116
%%%ubuntu 10.10 64bits rev34920
Render attached .blend.
Red Cube is not seen through Sphere as it would if Sphere use a raytraced transparency.
I created Material.001.
Then, I enabled Nodes.
And finally press "New" button on Material Node to create Material.002
Then, I just changed alpha in Transparency panel and trusted new Render Pipeline Options.
But in fact, newly created Material.002 have Transparency option disabled by default.
With new material properties, I have to change material or to create a new window to set inside material.
Before changing Material Properties, selecting a node was enough good to see all material settings.
Now, Transparency settings are not easier to understand; they are partially hidden.
Maybe Transparency panel should be renamed Node Transparency showing enable/disable box and Ztransparency/raytrace choice.
But material node options should be visible or render pipeline options should really overwrite corresponding options in node materials.
%%%
LLM Reasoning
Got it, let's analyze the two bug reports. First, look at the description and steps for each.
Bug report 1 is about transparency not working with Raycast Node in EEVEE. The steps mention using a Raycast node as a mask, which works in Cycles but not in EEVEE—mesh disappears. The key here is the interaction between Raycast node and transparency in EEVEE.
Bug report 2 is about Render Pipeline Raytraced Transparency not working. The steps involve creating materials, enabling nodes, changing alpha in Transparency panel, and issues with material settings (Transparency option disabled by default, UI confusion). This seems to be about the UI or material setup for raytraced transparency, not specifically the Raycast node interaction.
The first report is about a specific node (Raycast) causing transparency issues in EEVEE. The second is about general raytraced transparency in the render pipeline with UI/material setup problems. They don't describe the same issue. So the answer is No.
JSON Data
{
"llm_judgement": false,
"processing_time": 14.373948,
"duplicate_report_number": "26116"
}
Report flagged as NOT a duplicate by LLM
Render Pipeline Raytraced Transparency does not seem to work.
https://projects.blender.org/blender/blender/issues/26115
Duplicates: #26116
%%%ubuntu 10.10 64bits rev34920
Render attached .blend.
Red Cube is not seen through Sphere as it would if Sphere use a raytraced transparency.
I created Material.001.
Then, I enabled Nodes.
And finally press "New" button on Material Node to create Material.002
Then, I just changed alpha in Transparency panel and trusted new Render Pipeline Options.
But in fact, newly created Material.002 have Transparency option disabled by default.
With new material properties, I have to change material or to create a new window to set inside material.
Before changing Material Properties, selecting a node was enough good to see all material settings.
Now, Transparency settings are not easier to understand; they are partially hidden.
Maybe Transparency panel should be renamed Node Transparency showing enable/disable box and Ztransparency/raytrace choice.
But material node options should be visible or render pipeline options should really overwrite corresponding options in node materials.
%%%
LLM Reasoning
Got it, let's analyze the two bug reports. First, look at the descriptions and steps to reproduce.
Bug report 1 is about transparency not working with Raycast Node in EEVEE. The issue is that when using a Raycast node output as a mask for alpha/transparency in EEVEE, the mesh disappears (works in Cycles). Steps involve checking an attached blendfile and video showing the problem.
Bug report 2 is about Render Pipeline Raytraced Transparency not working. The steps mention creating materials, enabling nodes, changing alpha in transparency panel, but the new material has transparency disabled by default. Also talks about UI issues with transparency settings being hidden or confusing.
The key here: Bug 1 is specifically about Raycast Node + EEVEE transparency (alpha mask from raycast not working). Bug 2 is about general raytraced transparency in render pipeline, with steps involving material creation and UI issues. The core issues are different—one is a specific node (Raycast) in EEVEE, the other is general transparency settings in render pipeline. So they aren't duplicates.
JSON Data
{
"llm_judgement": false,
"processing_time": 15.16552,
"duplicate_report_number": "26115"
}
Report flagged as NOT a duplicate by LLM
Transparency nodes won't weork in EEVEE
https://projects.blender.org/blender/blender/issues/67779
System Information
Operating system: Win 10 64 bit
Graphics card: Intel inside
Blender Version
Broken: 2.80 rc1
Using transparency nodes in EEVEE produces blackness, even when mixed partially with other shaders; as if no shader was connected at all.
I am hoping this is actually a bug, 'cause otherwise I have been truly undergrateful for EEVEE.
LLM Reasoning
Got it, let's analyze the two bug reports. First, look at the descriptions and steps to reproduce.
Bug report 1: The issue is about transparency not working with Raycast Node in EEVEE. Specifically, when using Raycast node output as a mask, the mesh disappears in EEVEE (but works in Cycles). Steps involve checking an attached blendfile and video showing the problem.
Bug report 2: The issue is transparency nodes producing blackness in EEVEE, even when mixed with other shaders. No mention of Raycast Node here; it's a general transparency node problem.
So the key difference is that bug 1 is about Raycast Node + transparency in EEVEE, while bug 2 is about transparency nodes (general) not working. The descriptions are different, so they're not the same issue. Therefore, the answer is No.
JSON Data
{
"llm_judgement": false,
"processing_time": 12.474142,
"duplicate_report_number": "67779"
}
Report flagged as NOT a duplicate by LLM
Node vector blur not working with transparency
https://projects.blender.org/blender/blender/issues/25553
Relates to: #25552
%%%This may be related to a another transparency bug (25552).
For a moving object the very useful node vector blur effect does not appear to work when the object has Z transparency applied and passes in front of another object.
I have tested with flat planes, 3D objects with and without a subdivision surface modifier – the bug is very easy to reproduce and shows up on Windows and Ubuntu Linux.
In the attached file a transparent cube is animated to pass in front of and between two planes, one plane has a material and a cloud texture applied, the other has no materials. In the node editor I have set up a Vector Blur node with the samples reduced to 4 (to help things show up). If you render the current fame (frame 6) you can see the motion blur applied to the cube, but where it passes in front of the planes the effect disappears. Setting the transparency to raytrace will fix the problem, but then there is an issue with screen projection (see bug report 25552).
The Blender build number is: 2.26.0 r34161
Tested on AMD Phenom II X4 940 with a ATI 2400 HD graphics card and 3 GiB RAM.
WinXP and Ubuntu Linux 10.10.%%%
LLM Reasoning
Got it, let's analyze the two bug reports. First, look at the descriptions and steps to reproduce.
Bug report 1 is about transparency not working with Raycast Node in EEVEE. The issue is that when using a Raycast node output as a mask for alpha/transparency in EEVEE, the mesh disappears (works in Cycles). Steps involve checking an attached blendfile and video showing the problem.
Bug report 2 is about Vector Blur node not working with transparency (Z transparency) on moving objects. The issue is that when a transparent object moves in front of others, vector blur effect disappears. Steps involve testing with animated transparent cubes and planes, using Vector Blur node. It mentions setting transparency to raytrace fixes it but causes another issue.
The key here: Bug 1 is about Raycast Node + Transparency in EEVEE (mesh disappearing). Bug 2 is about Vector Blur + Z Transparency (motion blur not showing where transparent). These are different nodes (Raycast vs Vector Blur) and different contexts (EEVEE transparency with Raycast vs motion blur with Z transparency). So they're not the same issue. Therefore, answer is No.
JSON Data
{
"llm_judgement": false,
"processing_time": 16.143922,
"duplicate_report_number": "25553"
}