Shading maps is too slow in small zooms

onelook shared this problem 4 years ago
Not a Problem

When I have enabled shading maps (by srtm data), rendering map is very slow in small zooms. SRTM data should be pre-processed (by locus on external app) to allow quick rendering maps in small zooms.


Reproduction:

1) download SRTM data

2) select any large map (for example online global maps or Czech Republic map)

3) enable shadding maps on for example online maps

3) select zoom level for example 10

4) move the map by dragging

Comments (3)

photo
1

Hello,


I'm aware of this problem, but currently I see no simple way how to improve it.


There is a few major problems:


1. shading is directly drawn on map tiles. It means that there is only one image - map tile + shading at once. This speed up map rendering a lot and conserve a lot of memory


2. shading is generated dynamically also because various maps use various map projections. So caching is not too useful in all cases


3. major problem with speed is known missing using of hardware rending. Locus still use CPU (software rendering) for drawing a map tiles. It's related to this idea - http://help.locusmap.eu/responses/3d_maps_by_using_srtm_files


I'll close this issue, because it's how it works now. Anyway I do not want to leave it be, so when there will be any smart idea to improve, I'll do it. And I also hope that one day Locus will be drawing maps with OpenGL (hardware rendering), which speed up this task also.


Hope it's good answer for you.

photo
1

Hello, ok.


[czech] Myslím, že OpenGL není všelék. Vykreslovat výškovou mapu/stínování jako vektory dost dobře nedává smysl a textury musíš vygenerovat tak jako tak. Akorát tam bude celkem levná jejich případná transformace.

photo
1

[CZ]V půl čtvrté ráno, taky slušný :)

Nicméně OpenGL JE všelék. To že OpenGL využívá grafickou kartu neznamená, že vše musí být ve vektorech. Hardwarové vykreslování se stejně tak aplikuje na Bitmapy a i jejich transformace. To znamená, že čas který se nyní věnuje vykreslování grafiky, pak v podstatě nebude potřeba a využije se jinde.


No snad se jednou mého snu dočkám