Problems with HD terrain.

[WayneTrain12345]

I like the concept of having ultra-fine terrain to work with, but there are a few things needed that would make it perfect.

1. Let's have more textures please! 16 textures may sound like enough, but it's hard to make realistic landscape with only 16 textures. I myself hate the titling effect and I try all sorts of tactics to beat the effect!
5M terrain is awfully course, but it gives me 256 textures per baseboard. 5M terrain also works better for blending textures and rotating the textures as needed. It would be nice if there was an opaque option, which would make it easier to blend textures together. Maybe NV3 Games can introduce a mid-tier terrain, such as 2.5M grid with 128 textures, or 1.25M grid with 64 textures. Anyhow, we are currently in the land of extremes, course terrain with lot's of textures, or ultra fine terrain with hardly any textures. Personally, I'd prefer somewhere in the middle.

2. Hills flatten from a distance. I understand that the mesh count shrinks the further you get from it, and that's fine. What disappoints me is when I create a road overpass, and it collapses when I get further away from it. The height must be maintained to keep it realistic.

I am currently using 5M terrain for my routes, even though I have TrainZ Plus. At it's current state, HD terrain is best used for close up scenes. For large landscapes, the 5M is the best option for now, hopefully, it will change.

 

[derznovich]

I use HD terrain on my large route, the Wallace Branch, 70+ miles of mountainous terrain. I agree with your points but have found ways to adapt.

1. Regarding the texture limit, HD is very good at subtly blending textures, so I can use a very dark texture to darken up areas. I can also use the color layer although the 5m grid for this layer limits its usefulness.

2. I’ve created splines and small square scenery assets (on DLS) that enable you to put down payment cracks and stains and road ruts without needing a different texture.

3. For moving terrain, I try to cover as best as possible by adding trees to hide the movement from a mid or far distance. I also use concrete or ballast embankment splines for the most egregious cases where a track or road appears to float from middle distance. I would say there are only 4-5 spots where the moving terrain creates floating track or roads that are noticeable. More obvious are the cuts and cliffs where the jelly terrain effect is noticeable as you follow the train in rough terrain.

I believe it would be a good solution to be able to indicate on the route a few spots where HD terrain effects should not be culled. If you could paint just 1-2 spots per baseboard, it would do the trick.

N3V made this response on Discord a week or so ago:

Just to confirm, the 16 texture limit is a limitation of single pass terrain on current hardware; we may be able to relax or improve this in future, but there will still be limitations to it either way. The option is either stick to a coarse grid, such as 5m with the 'parallax' issues, or we move to a newer technology but take into account the limitations of that technology.

The texture boundaries will depend partially on how the texture is applied. It should be noted that HDT works at 2 different 'detail' levels, if you paint with larger brushes the textures will be painted to a larger grid, around 1m grid from memory. If you use a smaller brush, that forces it to paint to the full HDT grid, then there may be blotchy blending where the larger and finer grids meet. This is done to avoid further increase in file sizes beyond what is already seen with most HDT routes.

The smooth under selected is simply using the existing algorithms for the moment; we hope to improve these separately in the future, but there's no timeframe.

In regards to the 'moving' terrain, again for performance sake the terrain needs to have the detail level reduced as you move away. Since the terrain detail can be so much greater than before, it cannot just be done as individual LOD levels, so Trainz progressively reduces the detail the further away it is. This does mean that smaller details can blend out, and hence some care will be needed with route design to ensure it looks good. There is definitely room for this to be improved in time, but of course this can only happen if there is something for our dev team to actually work with; such as routes submitted to our team that showcase situations that have no other way to achieve the desired result, as there often /are/ options available to creators to achieve a good result.

 

[ApproachMedium]

The texture boundaries will depend partially on how the texture is applied. It should be noted that HDT works at 2 different 'detail' levels, if you paint with larger brushes the textures will be painted to a larger grid, around 1m grid from memory. If you use a smaller brush, that forces it to paint to the full HDT grid, then there may be blotchy blending where the larger and finer grids meet. This is done to avoid further increase in file sizes beyond what is already seen with most HDT routes.

In my experience, that threshold seems to be between 8m and 9m brush sizes. 8m seems to use the HD textures while 9m and larger use the SD (?) textures. So personally, I tend to keep my brush size to 8m or smaller for areas near tracks or detail scenes while reserving the larger brush sizes to cover larger, background regions.

- Joe

 

[WayneTrain12345]

I use HD terrain on my large route, the Wallace Branch, 70+ miles of mountainous terrain. I agree with your points but have found ways to adapt.

1. Regarding the texture limit, HD is very good at subtly blending textures, so I can use a very dark texture to darken up areas. I can also use the color layer although the 5m grid for this layer limits its usefulness.

2. I’ve created splines and small square scenery assets (on DLS) that enable you to put down payment cracks and stains and road ruts without needing a different texture.

3. For moving terrain, I try to cover as best as possible by adding trees to hide the movement from a mid or far distance. I also use concrete or ballast embankment splines for the most egregious cases where a track or road appears to float from middle distance. I would say there are only 4-5 spots where the moving terrain creates floating track or roads that are noticeable. More obvious are the cuts and cliffs where the jelly terrain effect is noticeable as you follow the train in rough terrain.

I believe it would be a good solution to be able to indicate on the route a few spots where HD terrain effects should not be culled. If you could paint just 1-2 spots per baseboard, it would do the trick.

N3V made this response on Discord a week or so ago:

Just to confirm, the 16 texture limit is a limitation of single pass terrain on current hardware; we may be able to relax or improve this in future, but there will still be limitations to it either way. The option is either stick to a coarse grid, such as 5m with the 'parallax' issues, or we move to a newer technology but take into account the limitations of that technology.

The texture boundaries will depend partially on how the texture is applied. It should be noted that HDT works at 2 different 'detail' levels, if you paint with larger brushes the textures will be painted to a larger grid, around 1m grid from memory. If you use a smaller brush, that forces it to paint to the full HDT grid, then there may be blotchy blending where the larger and finer grids meet. This is done to avoid further increase in file sizes beyond what is already seen with most HDT routes.

The smooth under selected is simply using the existing algorithms for the moment; we hope to improve these separately in the future, but there's no timeframe.

In regards to the 'moving' terrain, again for performance sake the terrain needs to have the detail level reduced as you move away. Since the terrain detail can be so much greater than before, it cannot just be done as individual LOD levels, so Trainz progressively reduces the detail the further away it is. This does mean that smaller details can blend out, and hence some care will be needed with route design to ensure it looks good. There is definitely room for this to be improved in time, but of course this can only happen if there is something for our dev team to actually work with; such as routes submitted to our team that showcase situations that have no other way to achieve the desired result, as there often /are/ options available to creators to achieve a good result.

Thank you for your input. I am very interested in the scenery splines assets and would like to download them if it's alright with you. By the way, what textures do you use for your HD layout?

 

[pware]

1. Let's have more textures please! 16 textures may sound like enough, but it's hard to make realistic landscape with only 16 textures.

That is a limit imposed by your hardware and not by Trainz. All games/sims that use HD (or its equivalent) have this limitation. Some (such as Unreal Engine) limit you to 8 textures per baseboard equivalent. And no, upgrading your hardware will not solve the issue - the hardware you would need has not yet been developed (a 128 bit CPU???).

You can overcome some aspects of the 16 texture limit by adding a Color Effect Layer.

 

[2995Valliant]

Colour effect layers are incredibly useful and can easily give the effect of treble the numbers of textures (ie 48) on a baseboard.