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Hi Everyone,
I am trying to make a realistic looking tree/plant leaf material that works in RT. I'm not sure to what extent the 2 sided material is supported with RT but from the tests I have done it seems that it doesn't really work at all for vegetation.
To start with I have the leaf shader that pretty much everyone seems to be using since this forum thread.
Its that Bertrand Benoit 2 sided material that seems to now be the standard. It works pretty well and is pretty realistic. For those who are not familiar - here is the shader tree.
The problem is that this shader looks absolutely terrible when rendered in RT. It just doesn't work.
To display the comparisions I have made a basic scene that has a physical camera, a series of flat planes with a similar leaf shader applied and a vray sun/sky backlighting the leaves (to get the nice translucency effect we all know and love). Using BF & BF in both cpu and gpu.
PS... the leaves at the bottom of the image - you are viewing the top side of the leaf. The leaves at the top of the image you are viewing the back side of the leaf (with the sun shining through it to show off translucency).
Apologies for the shitty renders I just wanted a small/quick scene that people can download easily and play with if they want. Scene is attached if you want to test for yourselves. Here are the results I got:
As you can see from above shitty renders:
1. It seems as though using a map in the translucency slot of a 2 sided material doesn't work in RT and seems to break the glossy reflections on the top sides of the leaves. And also breaks the shadows created by the leaves. And the level of translucency is way too low in the RT render.
2. If you remove the translucency map from the shader and just adjust the overall translucency value to a mid grey, you get an ok result in RT... BUT.... the level of translucency in the leaves is way too low. And the entire leaf is just 1 level of translucency ... ie the little veins which aren't translucent in real leaves show up as translucent which is not accurate.
3. So in order to achieve a stronger level of translucency I set the value to 255 (full white) but this just seemed to break the shader as well (in both RT and CPU). Though it did make the leaves a tiny bit more translucent.
4. When I just applied the front side of the 2 sided material to the leaves (ie just a standard vray material with no transparency) the leaves are much darker in RT.
5. In general, the colour of the leaves in RT are much darker (yeah i know RT is a completely different render engine etc etc but this is a pretty significant difference).
All of the above means that basically every tree in our library looks dark and awful when rendered in RT. The only way to get a semi-decent result (that only works when a long way from camera) is to go into each leaf shader and remove the translucency map and brighten diffuse maps.
So, please tell me there is a magic setting in the RT render settings that fixes this, otherwise we won't be able to use any of our library of trees and almost all of the commercially available trees would need a complete shader overhaul to make them useable in RT.
Has anyone been able to make nice leaf shaders in RT? Any ideas? Any thoughts?
I am trying to make a realistic looking tree/plant leaf material that works in RT. I'm not sure to what extent the 2 sided material is supported with RT but from the tests I have done it seems that it doesn't really work at all for vegetation.
To start with I have the leaf shader that pretty much everyone seems to be using since this forum thread.
Its that Bertrand Benoit 2 sided material that seems to now be the standard. It works pretty well and is pretty realistic. For those who are not familiar - here is the shader tree.
The problem is that this shader looks absolutely terrible when rendered in RT. It just doesn't work.
To display the comparisions I have made a basic scene that has a physical camera, a series of flat planes with a similar leaf shader applied and a vray sun/sky backlighting the leaves (to get the nice translucency effect we all know and love). Using BF & BF in both cpu and gpu.
PS... the leaves at the bottom of the image - you are viewing the top side of the leaf. The leaves at the top of the image you are viewing the back side of the leaf (with the sun shining through it to show off translucency).
Apologies for the shitty renders I just wanted a small/quick scene that people can download easily and play with if they want. Scene is attached if you want to test for yourselves. Here are the results I got:
As you can see from above shitty renders:
1. It seems as though using a map in the translucency slot of a 2 sided material doesn't work in RT and seems to break the glossy reflections on the top sides of the leaves. And also breaks the shadows created by the leaves. And the level of translucency is way too low in the RT render.
2. If you remove the translucency map from the shader and just adjust the overall translucency value to a mid grey, you get an ok result in RT... BUT.... the level of translucency in the leaves is way too low. And the entire leaf is just 1 level of translucency ... ie the little veins which aren't translucent in real leaves show up as translucent which is not accurate.
3. So in order to achieve a stronger level of translucency I set the value to 255 (full white) but this just seemed to break the shader as well (in both RT and CPU). Though it did make the leaves a tiny bit more translucent.
4. When I just applied the front side of the 2 sided material to the leaves (ie just a standard vray material with no transparency) the leaves are much darker in RT.
5. In general, the colour of the leaves in RT are much darker (yeah i know RT is a completely different render engine etc etc but this is a pretty significant difference).
All of the above means that basically every tree in our library looks dark and awful when rendered in RT. The only way to get a semi-decent result (that only works when a long way from camera) is to go into each leaf shader and remove the translucency map and brighten diffuse maps.
So, please tell me there is a magic setting in the RT render settings that fixes this, otherwise we won't be able to use any of our library of trees and almost all of the commercially available trees would need a complete shader overhaul to make them useable in RT.
Has anyone been able to make nice leaf shaders in RT? Any ideas? Any thoughts?
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