Topic: Is it possible to "mix" materials? And how to set bumpmap size?

[aceshigh]

Let make myself clear. Suppose I want to have a road. If I apply the asphalt material from Lumion, its a nice and all, but its gets pretty repetitive across the vast surface of the road.

Wouldnt it be possible for me to map a large bitmap of a road, with potholes, skidmarks, asphalt paintings (pedestrian cross, etc), utility holes, etc... and then MIX it with the default Lumion material, which is more detailed UP CLOSE? So as to have variety for the large scene and get up close and see the nice details of the default material?

If not, what if I just want to apply a detailed asphalt bumpmap over the large road texture? Because it seems to me that in Lumion the size of the bumpmap is always equal to the size of the diffuse texture... you change one, you change the other.

If I have an asphalt texture for a large area, lets say, 20x40 meters... and my bumpmap texture is for a small area 1x1 meters... I suppose the bumpmap would be stretched by Lumion to cover 20x40 meters? So the fine grain of the asphalt bumpmap would actually become big boulders bumpmapped?

[Morten]

Wouldnt it be possible for me to map a large bitmap of a road, with potholes, skidmarks, asphalt paintings (pedestrian cross, etc), utility holes, etc... and then MIX it with the default Lumion material, which is more detailed UP CLOSE? So as to have variety for the large scene and get up close and see the nice details of the default material?

Hi aceshigh, if you want to use materials with as many options as possible, you'll need to export the road object twice and make them overlap using an alpha mask:

A) Version A of your road should use an asphalt material from Lumion's Material Library.

B) Version B should be exported with your own custom texture coordinates as well as a custom diffuse texture with the potholes/skidmarks/asphalt paintings.

In addition, the texture will require an alpha mask so that Lumion knows where to show the potholes/skidmarks/asphalt paintings. Bear in mind that Lumion only supports 1-bit alpha masks, so a pixel is either visible (white pixel on the alpha mask) or invisible (black pixel on the alpha mask).

After importing this version of the model in Lumion, apply a Standard material and set the Reflection or Clip slider to the maximum value so it uses the alpha channel as a clipping mask.

The last step is to select both versions and run the Align command in the Context menu, so that the potholes/skidmarks version overlaps the other version.

Since both models occupy the same space, you will notice that they flicker as you move the camera around. Please follow the instructions in the Tips, Tricks and Shortcuts thread ("How to prevent flickering") to avoid this problem:

http://lumion3d.com/forum/f-a-q/lumion-2-tips-tricks-and-shortcuts/

[aceshigh]

to avoid flickering, you use the offset slider, isnt that? I already thought of that to use decals in buildings etc.

however, I dont think it will really look good with a 1bit alpha mask.

do the Lumion team plans on implementing a better alpha mask system (I dont know how many bits... I know alpha masks can be described as shades of gray, for the anti-aliasing).

[aceshigh]

oh, and btw, what about the bumpmap? Does the team plans to implement a different slider? At the 0 position, the bumpmap is set at the same size as the material diffuse bitmap. At other positions, you can set its size manually...

[Morten]

oh, and btw, what about the bumpmap? Does the team plans to implement a different slider?

I am not aware of any plans to add a second Scale slider for the 2nd texture slot, but thanks for the suggestion.

[Morten]

do the Lumion team plans on implementing a better alpha mask system (I dont know how many bits... I know alpha masks can be described as shades of gray, for the anti-aliasing).

The developers of Lumion have previously mentioned that it is virtually impossible for them to implement 8-bit alpha masks, but never say never...