problem sun/light reflection on custom vegetation (Planes)

[lumat]

I modeled a hedge of trees, like for fsx, with planes and transparency.
It's correct, but depending on the position of the sun, there is reflection on the planes as in the images below (the first on day and the second on morning)
Is there a way to remove this ? How to prohibit the reflection of light on these planes?

Also, does anyone know of a tutorial for creating custom trees that can be used on MSFS? I did not find. Methods used for FSX/P3D are far from perfect on MSFS.

Thank you for help

 

[Pyscen]

Actually, depending on the bushes they could be more right than you think. You are talking about 2 different shaders or game engines here. Comes down to what maps need to be adjusted and what maps are being used. Most likely the smoothnes/ roughness.between the 2 different game.engines

 

[lumat]

Thank you for your answer, Doug.
I don't sure to undertsand it
I fact, the object is made as for FSX/P3D, with planes as picture below, textured with transparency (alpha blend), double side. Roughness 100%. No specular, material mode "terrain Fake" (Standard give the same result)
Rendering is correct when the sun/light is high but there is many reflexion when the sun is low.

 

[=rk=]

How to prohibit the reflection of light on these planes?

Reflection is controlled by the green, or roughness channel of the Comp texture, but since you have referred your procedure to FSX, it seems likely you have not applied a Comp texture. Of particular note, the "Specular" adjustment has no effect in MSFS. It suggests the possibility you are using MCX, if so, you'll want to select the "MSFS" material template to avoid any confusion over material attributes.

Bear in mind that MSFS has a very liberal allowance for polygon count, especially for scenery objects, making cross plane tree modelling virtually unnecessary, unless you are replacing an entire forest. In fact, the SDK has a very thorough section on textures and asset creation and it specifically warns against using transparent backgrounds:

External Asset Creation

docs.flightsimulator.com

This is not to imply you are going about it wrong, but to suggest that things have changed immensely, since FSX was published. Do yourself a favor and review the SDK, if you've not already done so!

 

[Pyscen]

Made for FSX/ P3D is saying a lot when they both use different game engines. You aren't being specific on which P3D version that you are referring to. So, based on your answer I would think you are saying P3D v1 through v3. If this is so, then you are talking about 2 different workflows, specular and metallic (MSFS). or what most people suggest as PBR.

 

[Rotornut44]

the SDK has a very thorough section on textures and asset creation and it specifically warns against using transparent backgrounds

One of my discussions on DevSupport is to blame for this section.

For additional info: this isn't saying to avoid using transparency, but to use a solid, padded background in combination with a proper Alpha channel. You also have to look out for the pixel colors at the edge of your mask (white/black matting), as they will get exaggerated over a distance in the sim as lower quality mip-maps gets swapped in, leading to hazy looking textures at a distance.

For anything flat or cross-plane, you would still set Assume Vertical Normal in MCX. In the cases of smaller vegetation, I also tend to use Fake Terrain over Standard, as it cuts down on that lighting even more. Though, I don't do this for more 3d stuff or trees, as it forces "blend" for the alpha mode, which sorts weird against the sky. I also typically don't use full PBR for my vegetation. I find that in most instances it looks better with just Albedo and (sometimes) Normal, with both Roughness and Metallic set to 0.

Though, for your hedges, I would highly recommend going 3D. As Rick mentioned, MSFS can handle a lot more geometry and drawcalls than FSX or P3D could. As long as you are using proper optimization techniques to manage quad overdraw and texture memory. LOD0 would be your full-res. Do 3 additional LODs and decimate each one 50% less than the one before it. Drop your Normal textures at LOD1, drop Comp (if used) at LOD2, and either do vertex paint or use a 64px Albedo for LOD3.

For my own hedges, I used a modified cube to get the base shape and textured that with a tiling hedge texture (I did UV unwrap the base cube and paint it in Substance to just to generate AO for a basic COMP). Then I created a small texture with a leaf on it that used an alpha mask, mapped that to a plane, duplicated, scaled, and rotated them all around until I had a nice group going, then just started duplicating that group until I covered the entire outside. You do want to find a good balance to the number of leaves and scale that you use to cover an area though, as you can get carried away quite fast and have an overly dense shrub with a ton of triangles/verts. Also, don't forget to join all the leaves to the base cube(Object Mode - Ctrl+J in Blender) before export/LOD generation, else it will treat each seperate part as a drawcall and tank performance!

For instance, mine comes out to 11,433 triangles / 22,923 verts for the 10-meter model. Double that, minus a few hundred for the 20-meter (I know, I know - I didn't feel like looking).

 

[lumat]

Thank you so much for your answers. It's a great help.

Chris, I made a hedge as you explained. The result is really better. I must to make some settings (colors, and I forgot the rotation of the leaves on Z axis ! ). But it's nice.
I will try to improve this
Just a question : you say Tiff is better. Better than PNG for alpha textures ? Why ?

 

[Rotornut44]

Just a question : you say Tiff is better. Better than PNG for alpha textures ? Why ?

Sorry, I had that backwards - late night thought process! I'll remove that part as to not confuse.
PNG is the better format, but you need to make sure that you export it with the alpha channel not applied! A quick way to tell if you did it properly would be to load the compiled DDS into DXTBmp and if you see the texture with padding in the main window, and an alpha in the top right, then you're good to go. If the background of the main window has solid color around your UV areas, it exported wrong and could contribute to that discoloration over distance.

Another note which I have amended to my original post above: Don't forget to join all the leaves to the base cube (Object Mode - Ctrl+J in Blender) before export/LOD generation, else it will treat each seperate part as a drawcall and tank performance!

 

[lumat]

Thanks, I've forgot to join leaves and cube !
Sorry, what do you mean by the "alpha channel not applied". Usually, I make the texture image with Gimp : Selection of the transparency zone, add a layer mask and applied it.
Maybe a wrong method (Ah, FSX !!! ) and it's not the better way for what i have to do :/
Here a screen of the dds for the 2 objects (cube and leaves).

 

[Rotornut44]

Hmm. I'm not as familiar with processes in Gimp as I use Photoshop, but in Photoshop you can apply an alpha channel to the background so that the image pixels take on the transparency. DDS will pull an alpha from this, but the once transparent areas will turn black on the main texture, as you can see in your screenshots. In Photoshop it is as simple as leaving the alpha channel be after you create it. Don't click any options that have anything to do with applying it or merging it down. You should be able to disable the alpha layer in Gimp and verify that the main image has no transparency. Then just export it like that as a 16-bit PNG (All of your textures should be 16-bit BTW, not the default 8-bit).

Double check the PNG export settings, but I would think it should just retain it automatically..

 

[lumat]

I'll see how to do that in GIMP

Can I ask you on more question : how do you make great plants like the trees, trunk and leaves. Are there some particularities ?

 

[Rotornut44]

The trees currently in my library were all bought or downloaded then optimized, but moving forward I've started to play around with Tree It. They have some sample projects on their website that you can download and play around with as a starting point. It gives pretty believable results and can be made low-poly. I'm personally still trying to get the hang of it. You just have to play around with sliders until you get something decent.

 

[rhumbaflappy]

TreeIt has some real possibilities:
https://www.fsdeveloper.com/forum/threads/custom-vegetation-draw-distance.456116/post-912021

It appears these were made with TreeIt, and the author wisely uses LODs. You could use his library and save some time:
https://flightsim.to/file/56359/ethnicfs-vegetation-library

Get TreeIt:
http://www.evolved-software.com/treeit/treeit
You can also get it on Steam for a few dollars. And Steam will keep it in their servers (a little insurance that the program will be available if the author takes down his website.

You can use TreeIt to create trees that can be redistributed... but the included tree examples cannot be redistributed. (You can use the examples as starting points for your own distributable trees, but they must be modified).

 

[Rotornut44]

Since I use LODs for my trees, I found another trick to help with the distance culling.
I will take my branches and scale by individual origins in Blender, and then for each LOD, I will scale the branches up a fixed distance, so they get bigger and bigger the further down the LOD trail you go. It doesn't completely stop the culling, but you can squeeze some more distance out of it until it does, and keep your trees looking more dense. Obviously there is a fine balance here, and it may not work with every tree setup.

Edit: Something else I just thought of, but haven't tried. You may also be able to play around with separate materials for your LODs and lower the mask threshold. This would make the trees appear more dense and may help over a distance. You could do it in stages across a few LODs to make the transition less noticeable. Most culling you see on 3D trees over a distance is due to transparency and mipmaps, so in theory...

I'm reworking my pine trees today, so I'll have to play around with it.

 

[lumat]

Thank you so much, Dick and Chris, for these last answers. I didn't know Tree it. It seem to be great ! I'll try it

NB : Chris, Finally, it's easy too with Gimp for the channel not applied, just don't apply it !!!

 

[Rick Celik]

Does anyone have a workflow on how to export from TreeIt into 3dsmax, I can get the model into 3dsmax, its just how to go about texturing and the UVWs?

 

[Rotornut44]

Does anyone have a workflow on how to export from TreeIt into 3dsmax, I can get the model into 3dsmax, its just how to go about texturing and the UVWs?

If you did an export to FBX and brought it into 3ds, it should have retained the UVs, so all you would have to do is convert the materials to a MSFS material and then add the textures. You shouldn't have to redo any of the UV mappings unless you opted out of it in TreeIt somehow. At least that's how it was for me in Blender.

 

[rhumbaflappy]

Does anyone have a workflow on how to export from TreeIt into 3dsmax, I can get the model into 3dsmax, its just how to go about texturing and the UVWs?

Just curious, but if you already have the trees made in Blender, why not just compile the glTF there?

 

[Rick Celik]

If you did an export to FBX and brought it into 3ds, it should have retained the UVs, so all you would have to do is convert the materials to a MSFS material and then add the textures. You shouldn't have to redo any of the UV mappings unless you opted out of it in TreeIt somehow. At least that's how it was for me in Blender.

Yes just realized that, the only thing I have to do is align the UVWs with the texture, the UVWs are overlapping each other so they still need to be sorted in the UVW space.

Just curious, but if you already have the trees made in Blender, why not just compile the glTF there?

The trees are made in TreeIt not blender, I dont use blender. My question was the workflow from TreeIt to 3dsmax.