The rendering results of projected textures vary with different resolutions.

[394452216@qq.com]

A: 1000X1000
B: 3500X3500
Corona 12 update 1

[394452216@qq.com]

Render B

[romullus]

That is expected behaviour. Blur in 3ds Max is used to avoid aliasing, its results depends on texture size in rendered image - the smaller texture will be, the more it will be blurred. If you want that blurring would stay constant independently on texture's size, you need to use blur offset, not the blur. You can read about this in Max's documentation: https://help.autodesk.com/view/3DSMAX/2024/ENU/?guid=GUID-8AE3643F-BDB4-498B-B220-92646FC8A562

[pokoy]

If this is about map filtering, it is expected but certainly not the degree visible here.

However, it looks to me like this is about texture from a light (gobo), or shadows cast through some tree-like geometry above, right? Not a texture in a material on an object.

If that's the case, it's probably due to the fact that Corona resizes environment maps (both HDR maps and Corona's Sky&Sun) internally. The default value works for most cases, can however result in blocky artefacts from the sun which would look exactly like what's happening here.

The solution is to use this in the string options window in the render dialog window (development/experimental stuff), restart the render if you're updating this while in IR:
int lights.envResolution = 4000
 
AFAIK the default valuue is 1000, try 2000, 4000 or some other value that improves the shadows. Keep in mind it will take longer to render and might result in a noisier image.

[pokoy]

Just to add this: IF the issue is blocky shadows, I found a thread that reports this with some discussion on the topic and the solution (same one I posted above).

[maru]

@394452216@qq.com - are you still having this issue? Could you please contact us about it at https://support.chaos.com/hc/en-us/requests/new

The solution is to use this in the string options window in the render dialog window (development/experimental stuff), restart the render if you're updating this while in IR:
int lights.envResolution = 4000

AFAIK the default valuue is 1000, try 2000, 4000 or some other value that improves the shadows. Keep in mind it will take longer to render and might result in a noisier image.

Actually, now this is available as a checkbox in the Scene > Environment rollout. :)

[pokoy]

Ah thanks - this reminds me of switching... sorry for the confusion then.

[maru]

@394452216@qq.com - is it possible that the scene was originally made in some super old version of Corona?
Try this:
1. Open the development/experimental stuff rollout - here is how - https://support.chaos.com/hc/en-us/articles/4528523195537
2. Make sure that you have "texmap filtering" set to "all but opacity"
Once you do that, the blur parameter and render resolution should have no effect on the appearance of the opacity map (or minimal).