Feature Request: Shadow Simulation

A tool to simulate shadows on the loaded model would be great.
Two sliders DAY of Year and Time of Day.

A next step would be an option to generate color texture overlay , a heatmap of hours per day of the sunlight to pick good spots for the panels.

Similar to shademap.app that does that in 2.5D


Hi Maciej,

Thank you for your suggestion.

CesiumJS does have the ability to support shadow display. See this sandcastle example with shadows enabled. There is a selector for the day and time at the bottom of the view. It is not two individual selectors, however it is a feature that is available today to let you set the date and time.

Currently Cesium ion does not support the specialized task of doing sunlight and shade analysis. That is something that we may consider adding in the future.


Have seen your shadow demo it is impressive in terms of the shadow quality, I also looked at some community implementation of shadow/viewshed that are buggy as hell. I realize that you might want to sell that feature but I would convince you not to, as more features free the better adoption of your platform as industry standard.

Since you are considering to add such a features I have one more suggestion. Regarding your time line slider. It is now designed specifically for some event tracking like plane flights or so. It is completely useless when it comes to the shadow analysis. In that case you need to be quickly jump between December and June while having the same Hour of the day. So thats why I would sugest adding alternative version there

and second one or single switchable to the months of year

I wrote a master thesis on th UX, DM me if you want turn Cesium into killer app for solar energy industry, all things available now on the market are subpar, thats why I’m here researching.

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Thanks for the suggestion. The timeline tool is a feature of CesiumJS. I’ve tagged their team to let them know about your suggestion.