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Can anyone explain why this happens and how to avoid it? This should be a simple flat plane with a rough scratchy black plastic material. It mostly works but at some angles it looks as if theres a large grid running over the the entire object.
The lines are aligned with the flat projected material, however the size and spacing of the bands does not match the square projected texture, plus its an octane noise so there should be no repeating issues. I cant shrink the projection with an octane projection nodes because as we all know by now octane handles small bumps very poorly (might be fixed in 2023 maybe)

octane 2022.1.1 R5
c4d R26.107
gf 3090

c4d file attached.

You're projecting the texture using a cubic projection on the texture tag, that is so so small (0.05cm) that what you're seeing is the renderer trying to filter those tiny tiny tiny bumps. Fit your projection to the object and then adjust the scale of the noise with a transform node to get where you want.

But scaling bumpmaps down via the node system completely wrecks how the look in renders.

Here's my original render Here I have scaled my c4d projection up 10x and scaled down the bump in the octane node 10x And heres 100x larger in c4d (50cm wide) and 100x smaller in the octane node Wrecked would be putting it mildly.

Also the scale isnt really that small, I have c4d set to work in mm as the base unit instead of the default cm, so effectively to the render engine its like I have the bump scaled at 0.5cm which is well within the realm of sensible scales.

Here's the irony. If I scale my c4d flat projection up to the full width of the object, lets say 200x larger. convert that to uvw mapping, then in the texture tag in the object manager I set the uv scale down to 0.5, this will often look the same as the original, but with no lines. It works 90% of the time, but 10% of the time it looks slightly different but still bad. Im trying to work out if im fundamentally doing something wrong or if theres a better way. Scaling noises for bumps in octanes node system is 100% no-go because it universally looks like junk.

boxfx wrote:But scaling bumpmaps down via the node system completely wrecks how the look in renders.

Here's my original render

c4dscaled.jpg

Here I have scaled my c4d projection up 10x and scaled down the bump in the octane node 10x

scale mid.jpg

And heres 100x larger in c4d (50cm wide) and 100x smaller in the octane node

octanescale.jpg

Wrecked would be putting it mildly.

Also the scale isnt really that small, I have c4d set to work in mm as the base unit instead of the default cm, so effectively to the render engine its like I have the bump scaled at 0.5cm which is well within the realm of sensible scales.

Here's the irony. If I scale my c4d flat projection up to the full width of the object, lets say 200x larger. convert that to uvw mapping, then in the texture tag in the object manager I set the uv scale down to 0.5, this will often look the same as the original, but with no lines. It works 90% of the time, but 10% of the time it looks slightly different but still bad. Im trying to work out if im fundamentally doing something wrong or if theres a better way. Scaling noises for bumps in octanes node system is 100% no-go because it universally looks like junk.

I looked into this.

Its just a gamma issue

I am pretty sure if you use the projection in the Tag its converting the noise to sRGB, while if you use just nodes in the octane material, its still linear.
If I apply a color correction node to the one I mapped with a projection node and scaled down via a transform node and set the gamma to 2.2 I get the same look you are after

sorry forgot the file