Tracks Some advices for creating trees for Assetto Corsa mod track?

[Fat-Alfie]

It works just fine. I use 6-tri trees in the distance to fill up the environment where lighting isn't as critical. Halving the number of tris per tree can make a difference if you are adding 70-80,000 trees

 

[ChicAnne]

Does that work well with the kstree shader? My understanding was that the subdivided y-tree was the only thing that worked with it.
Also, ChicAnne, your track is looking bad*ss

Thank you very much, you are very kind.I hope it will bring joy to many, I know it does to me. After a year of work, the track is still in it's early stages but it's growing strong with the help of the community. SIM racers = amazing people ❤

 

[ChicAnne]

It works just fine. I use 6-tri trees in the distance to fill up the environment where lighting isn't as critical. Halving the number of tris per tree can make a difference if you are adding 70-80,000 trees

OMG it's you! The first thing I want to say, I love your tracks, thank you for making them! And thanks for helping out here of course! Can I ask you something? My trees now have 24 triangles, is that OK, can I finally move on? I'm asking for the trees set somewhere in the middle plan. Thank you in advance

 

[Fat-Alfie]

Thanks! 24 sounds fine to me. I use 6-tri trees for the distant landscape, but for all the trees next to the edge of the track I use a 24-tri model which gives better lighting effect.

I am also considering trying out some very simple 1-tri trees on the horizon, for the first time. I think Kunos used these on Imola, but I'm not sure.

 

[Fat-Alfie]

I just did a quick test with 1-tri trees on my Bremgarten track, and it looks quite promising

I filled a 2 km² area with 4000 trees (so, 4000 tris) and it looks quite effective. I just used 3ds max's Scatter feature, giving each tree a few degrees of random rotation and +/- 25% random scale, and as they are so far away from the camera you don't have to worry about seeing the invisible back of them.

Time to map out the rest of the distant landscape, I think

 

[NightEye87]

Looks absolutely fine!

 

[ChicAnne]

I just did a quick test with 1-tri trees on my Bremgarten track, and it looks quite promising

I filled a 2 km² area with 4000 trees (so, 4000 tris) and it looks quite effective. I just used 3ds max's Scatter feature, giving each tree a few degrees of random rotation and +/- 25% random scale, and as they are so far away from the camera you don't have to worry about seeing the invisible back of them.

Time to map out the rest of the distant landscape, I think

Now that looks amazing. Thank you for all the info!

 

[Fat-Alfie]

Well, that worked! And it was quick and easy to do, too

I just took the texture for the distant terrain, isolated the forest areas, digitied them to create spline shapes, converted them to polys, shrink-wrapped them to the terrain mesh and then used them to spawn 76,000 trees. I managed to cover 175 km² in about an hour!

 

[toxiciron]

Geez man, that’s genius! I always thought square billboards were the most efficient, i never considered single triangle, just cut that crap in half, lol. I’d be curious how to do that stuff with blender. Like I’m not aware of how to convert a black and white picture like you’ve made to splines in blender, nor how to scatter objects within a spline, nor how to get all the trees to face toward the track, lol. I’m working on my first track and didn’t go anywhere near 125 sq km because of the nightmare of covering it in trees (it’s near Seattle, heavily foresty). But with your methods, there’s hope!

EDIT: Okay, so I’ve done a little research. Apparently you can make a black and white image like you did (shouldn’t be too hard in gimp), then bring it into a vector editor ( I have a free one) and use auto-trace so that it vectorizes it. Then, you can save it as an svg, then you can import that vector shape into blender.

 

[Fat-Alfie]

Yes, that's pretty much how I did it. I didn't do anything fancy to make the flat trees face the road, though. I just split the spawn object up using the circuit as the centre point, and then made sure the trees in each section were perpendicular (or, as much as possible) to the circuit:

The radius of the distant terrain is about 7.5km so some of the trees won't be visible from the circuit, but I think they're worth adding for such a small performance cost

 

[NightEye87]

Geez man, that’s genius! I always thought square billboards were the most efficient, i never considered single triangle, just cut that crap in half, lol. I’d be curious how to do that stuff with blender. Like I’m not aware of how to convert a black and white picture like you’ve made to splines in blender, nor how to scatter objects within a spline, nor how to get all the trees to face toward the track, lol. I’m working on my first track and didn’t go anywhere near 125 sq km because of the nightmare of covering it in trees (it’s near Seattle, heavily foresty). But with your methods, there’s hope!

EDIT: Okay, so I’ve done a little research. Apparently you can make a black and white image like you did (shouldn’t be too hard in gimp), then bring it into a vector editor ( I have a free one) and use auto-trace so that it vectorizes it. Then, you can save it as an svg, then you can import that vector shape into blender.

Or "just" use a texture in your particle system and set it to "Density". Works fine with a quick test:

The process is a bit weird. Especially setting up the scattering itself. Blender works best on the Hair system and it has some querks. But once that is set up (any online tutorial should get you there, although it can really use a full dedicated written tutorial), go to the particle settings of the emitter object (can be a copy of your terrain), scroll down to Textures, create a new one and open it up in the texture tab (the

icon next to it), set the Influence to Density and Mapping to UV and select the correct UV map.
You can do the same for the scale of the trees by using the same or a new texture and setting the correct influence.

 

[ChicAnne]

Yes, that's pretty much how I did it. I didn't do anything fancy to make the flat trees face the road, though. I just split the spawn object up using the circuit as the centre point, and then made sure the trees in each section were perpendicular (or, as much as possible) to the circuit:

The radius of the distant terrain is about 7.5km so some of the trees won't be visible from the circuit, but I think they're worth adding for such a small performance cost

Everything this, it's just too overwhelming for me, at least for now. It's really impressive, don't get me wrong, but lot's of everything. I just click my trees around the map May I use this opportunity to ask you one more question if you don't mind. When creating DDS textures for trees, should I generate mipmaps or no? I use 2048x2048 72bpi atlases with four trees on them. Thank you once again. Many of you made this process much easier.

 

[Fat-Alfie]

Yes to the mipmaps.

I also use 2k textures with 4 trees per texture (except for my 6-tri and 1-tri distant trees, which use a 2048x1024 texture).

 

[Stereo]

Probably mostly applies to pines, but one fun trick is packing the trees facing away from each other (2 upward, 2 downward) so if the ground alignment varies a bit, the texture just shows trunk from the other tree, and you get a bit of extra height variation free.

 

[toxiciron]

Yes, that's pretty much how I did it. I didn't do anything fancy to make the flat trees face the road, though. I just split the spawn object up using the circuit as the centre point, and then made sure the trees in each section were perpendicular (or, as much as possible) to the circuit:

The radius of the distant terrain is about 7.5km so some of the trees won't be visible from the circuit, but I think they're worth adding for such a small performance cost

Okay so I think I'm too lazy to find a way to split the tree platform meshes into 6 parts, but I did use your idea to make a very low-poly tree. I just made a single-triangle tree, linking the same material/texture as the 'full' tree, and duplicated each face (twice) and spun them 120 each to make a funky pyramid tree. That way I don't have to rotate them, I can just apply random z-rotation. Still way better than 24, but technically I guess it's 3 times slower than single-tri trees. One disadvantage is that they can look rather thin from one angle if the tree is asymmetrical.
24 poly vs 3 poly

 

[toxiciron]

Probably mostly applies to pines, but one fun trick is packing the trees facing away from each other (2 upward, 2 downward) so if the ground alignment varies a bit, the texture just shows trunk from the other tree, and you get a bit of extra height variation free.

What does that mean, packing trees? And what is up and down? All I know about texture work is UV unwrapping and applying, if there’s something fancy going on with the orientation I don’t know about it, lol

EDIT: NM, I just didn’t understand. You mean one right side up tree and one upside down connected to it, lol. Don’t mind my idiocy

 

[ChicAnne]

Hey guys, I wanted to jump in and ask something because I'm also having basic issues with trees.
I've figured out how to model a Y tree (ChicAnne I can go into detail because after some trial and error, I can do it relatively quickly), but the problem is that the lighting is all screwed up in the ksEditor and game. I'm very much in the rough draft stage but here's my problem.
View attachment 473315
It's like it's casting a completely black shadow on itself. It looks fine in blender, but not in the engine. I tried LilSki's advice and subdivided in half top to bottom, but then it turned out like this:
View attachment 473316
I'm wondering if the issue is because I did not explode it. All I did was duplicate the faces and flip the normals on the duplicated faces. It seems kinda weird doing that because these trees are each like 30 triangles now.
I also thought maybe it was doing that because the bottom was sticking through the ground, so I tried floating it above ground but it still does it.

Hey! I am really sorry to bother you but can't figure this out on my own. Any ideas on what to do next? I am really getting desperate here I got the trees working in RTB, KS editor and AC. Shadows are good, tree shader works fine, I even named the components the way they should be. I was so happy for placing new trees in the game itself that I didn't notice this issue in RTB. So, this problem happens when I orbit the camera downwards from the tree. I have seen this problem in KS editor and managed to fix it but this time the problem is in Race track builder and I have no solution or ideas what to do.
Things I have tried doing:
GIMP
- tried 4096 x 4096 72 bpi and 2048 x 2048 bpi atlases with four tree textures on them
- tried both DXT5 and DXT3 DDS textures - DXT5 exports in a bad way, DXT3 gives a new resolution which is not 2 by 2
- tried mipmaps and no mipmaps - same problem as above persists
- had four tree layers merged to one and also tried without merging, for all other tests I didn't merge the layers - both ways the problem above persists
PHOTOSHOP
- tried 4096 x 4096 72 bpi and 2048 x 2048 bpi atlases with four tree textures on them
- Nvidia DDS export as DXT5 - looks great, imports in RTB, problem persists
- Nvidia DDS export as DXT3 - looks great, imports in RTB, problem persists
- had four tree layers merged to one and also tried without merging, for all other tests I didn't merge the layers - at this point I realized I shouldn't merge layers before exporting to DDS
BLENDER
- I tried setting the pivot point the right way (set origin to geometry and that should be enough, right?)
- tried setting the origin to the floor in the middle of the tree
- couldn't figure out if my vertices were merged, auto merge is off so I guess they are not as it should be
- managed to make the crease between the planes smaller - fixed the visibility of the crease in-game but the problem above still persists
- do I need to explode the object like you would do in Sketchup?
XPACKER
- tried both with and without kstree shader option - without the kstree shader the problems happens in the same way only it's reversed (when I orbit upwards)
- tried alpha blend and alpha test (should be alpha test, right?)
- tried dissolve shader only - ended with no transparency of course

Sorry for wasting your time but with the help from all the tutorials and forums I ended up clueless, really. Thank you in advance! ☺

 

[toxiciron]

Hey! I am really sorry to bother you but can't figure this out on my own. Any ideas on what to do next? I am really getting desperate here I got the trees working in RTB, KS editor and AC. Shadows are good, tree shader works fine, I even named the components the way they should be. I was so happy for placing new trees in the game itself that I didn't notice this issue in RTB. So, this problem happens when I orbit the camera downwards from the tree. I have seen this problem in KS editor and managed to fix it but this time the problem is in Race track builder and I have no solution or ideas what to do.
Things I have tried doing:
GIMP
- tried 4096 x 4096 72 bpi and 2048 x 2048 bpi atlases with four tree textures on them
- tried both DXT5 and DXT3 DDS textures - DXT5 exports in a bad way, DXT3 gives a new resolution which is not 2 by 2
- tried mipmaps and no mipmaps - same problem as above persists
- had four tree layers merged to one and also tried without merging, for all other tests I didn't merge the layers - both ways the problem above persists
PHOTOSHOP
- tried 4096 x 4096 72 bpi and 2048 x 2048 bpi atlases with four tree textures on them
- Nvidia DDS export as DXT5 - looks great, imports in RTB, problem persists
- Nvidia DDS export as DXT3 - looks great, imports in RTB, problem persists
- had four tree layers merged to one and also tried without merging, for all other tests I didn't merge the layers - at this point I realized I shouldn't merge layers before exporting to DDS
BLENDER
- I tried setting the pivot point the right way (set origin to geometry and that should be enough, right?)
- tried setting the origin to the floor in the middle of the tree
- couldn't figure out if my vertices were merged, auto merge is off so I guess they are not as it should be
- managed to make the crease between the planes smaller - fixed the visibility of the crease in-game but the problem above still persists
- do I need to explode the object like you would do in Sketchup?
XPACKER
- tried both with and without kstree shader option - without the kstree shader the problems happens in the same way only it's reversed (when I orbit upwards)
- tried alpha blend and alpha test (should be alpha test, right?)
- tried dissolve shader only - ended with no transparency of course

Sorry for wasting your time but with the help from all the tutorials and forums I ended up clueless, really. Thank you in advance! ☺

So you said they were working before? Did you change the tree geometry since then? That looks pretty similar to the issue I had before on the last page. Also, you do have to do that story book explode thing, that was my issue.

 

[ChicAnne]

So you said they were working before? Did you change the tree geometry since then? That looks pretty similar to the issue I had before on the last page. Also, you do have to do that story book explode thing, that was my issue.

I want to apologize for my previous post but I am going crazy here Long story short, would you mind sharing your tree model with me? Could I just check if your model works in RTB? That would help me so much

 

[toxiciron]

I want to apologize for my previous post but I am going crazy here Long story short, would you mind sharing your tree model with me? Could I just check if your model works in RTB? That would help me so much

Yeah, here you go (and I guess all the onlookers, lol). Just take off the txt at the end.